The beam divergence of laser target designators are typically in the nought point parts milliradians. An enormous beam would be wasting laser energy all over the place - which is not great from the POV of a portable system with minimal power requirements.
A laser target marker projects a small spot on a target... the energy is concentrated on that spot but does not reflect a narrow beam... it appears like a small sun shining in all directions, which the laser guided munitions detect and home in on... the laser guided weapon could be coming from some distance so the reflection has to be as bright as possible, while the target might not be a good colour or texture to reflect the energy well.
I seem to remember a situation in a conflict where the guy with the laser target marker decided to shine his laser beam on a particular soldiers helmet to get a good reflection for the very large aircraft delivered bomb that was coming... he wasn't some sort of sadist... the helmet gave a good laser reflection and would result in a good track for the bomb.
The laser beam riders however like Kornet don't look at the target, they look back at their launch platform so a fine narrow beam is actually bad.
What they actually use is four beams in different frequencies.
To describe it to a person it is easier to use visible frequencies, so say top left is red, right is blue, bottom left is yellow, and bottom right is green.
The centreline of the beam means looking back you see all four colours, but if you are flying high and to the right you see blue so the missile itself realises it must be high and to the right so it uses its control surfaces to descend and turn left... if it goes from blue to green it knows it is now too low and levels off and starts to climb again and keeps turning left... if it goes from blue to red then it stops turning left and starts to turn right again and continues to descend.
When it sees all four colours it knows it is in the centre of the beam.
Moving targets means it will be constantly manouvering to get into the centre of the beam... a big wide beam means the centre of the beam can be pointed more aggressively because there is less risk of the missile no longer seeing any colour and losing command guidance.
Borders between one colour and another means two colours will be visible and depending on which colours they are it can stop manouvering in that direction and continue in the other direction till all four colours can be seen.
As I mentioned 1km before target impact a Vikhr will have its aimpoint dropped 6m on to the point of aim of the target, and therefore the missile which was flying 6m high to avoid fences and bushes and other things on a battlefield will then drop down to the line of sight to hit the target.
Tests showed the CEP of the Vikhr was 80cm or 0.8m at 8km which is pretty damn good... that was in the 1990s so it is presumably better now.
For a target 8km away the laser beams for beam riding missiles only has to travel to the target, so 8km.
If it was a SALH like a laser homing Hellfire... say an Apache is attacking a target 6km away from its position, the laser beam from the Apache needs to be visible from 12km... it travels 6km from the helicopter to the target, and then has to be visible from the helicopter for the Hellfire to get a lock before launch.
The fact that a radar pod with Khrisantema allows target engagement in zero visibility means getting the enemy to pop smoke is a good thing because the Mi-28N with Khrisantema and the radar pod can see through smoke and also guide its missiles through smoke and heavy snow or rain or dust or blazing fires that would reduce the performance of optics or laser beams and render them useless.
Losing a complement of smokescreen is far better than losing a complement of tanks. Establishing an ambush situation where your guys let off the first shot is no trivial feat. Lots of work would have to be done identifying likely routes of advance, making sure they follow that route, and of course preparing defensive positions, etc. All to lose that initiative with a couple of well-placed smokescreens.
The Russians/Soviets had equipent to generate smoke screens kms long for landings or attacks, but they also have battlefield radar equipment down to equipment mounted on HMGs and Automatic grenade launchers to deal with zero visibility situations where targets are moving on a battlefield behind smoke screens...
The Russians are still understandably reticent over expensive weapons with active sensors onboard. A neat alternative could be to use the Orlan-10 model: offload the sensors to a cheaper (and easily replaceable) platform that could still be reused. The Russian version of Javelin could easily be the Gran guided mortars guided by an Orlan-10 with a laser target designator. For the price of a single Jav missile you retain mass effect and precision
Their Ka-52s seem to be intended as recon helicopters that could use their radar to scan the battlefield for targets... they have included pylon mounted boxes for drones that can be sent forward into dangerous areas to scout ahead, but with Khrisantema they could just as easily carry the wing pod and a pylon of missiles and use that for finding and engaging targets in zero visibility.
AFAIK most of the weapons the Mi-28 and Ka-52 carry are command guided or laser beam riding, now with command guided weapons like sturm and ataka they used to use optics to detect targets and radio command antenna to guide the missiles using optical target and missile tracking with the radio command antenna sending course corrections... essentially replacing a wire link. As such even with MMW radar both aircraft cannot fire missiles in any weather conditions or zero visibility conditions because either the target can't be detected or the missile cannot be directed (with laser beam riding)
With the Khrisantema and radar pod they should be able to use their own radar to find targets and then scan targets with the radar pod to get locks and launch radar pod guided missiles at the targets all without the target being visible... say a monsoon rain or dust storm or heavy cloud and fog or heavy snow.
Even if the target detects the MMW radar and pops smoke it wont matter, and if they move the radar will continue to track them.
By any measure, K-52 is used more extensively in this war. I believe that MoD will end up changing purchase contract till 2027 to increase purchase numbers for K-52M at the expense of Mi-28NM.
The Ka-52 is oriented as a scout helicopter.... it is very heavily armed but its US equivalent would be the Commanche but without the stealth of course, which is just useless for a helicopter anyway. The Mi-28NM on the other hand is an attack helicopter, and in that regard I don't think it is inferior in that role... the upgraded NM model has new optics and systems and looks rather impressive... more so when airburst 30mm cannon shells are introduced and new optics and systems and new weapons are added like guided rockets in rocket pods and a variety of new missiles including SOSNA and Hermes... and upgraded radar.
There have been claims that MANPADS make helicopters too vulnerable on a modern battlefield, and actually many ATGMs are dangerous for low and slow aircraft as well, but the Russians seem to not have lost as many helicopters as such claims would suggest were likely... their self defence systems and tactics appear to make them quite viable systems.