Simulators without engine means that they have been hanged on an external pylon instead than in the bomb bay?
Good point. Normally when carried by a fighter these dummy missiles are mounted on the wing and use their nose mounted radar or IR sensor to find the target and get a lock before launch. It is not fired because it is only used for testing to see if the target can be locked and therefore fired upon by that system, but in this case the S-70 does not have external weapon pylons so this was an internal weapon mounted AAM system.
The question is, do the AAM pylons include a system to extend them outside the aircraft to expose their Radar or IR sensors for locks before launch, or are these new version missiles that can be given target data inside the weapon bay and therefore be lock on after launch weapons...
"will make it possible to assess the coupling of the drone's avionics with missile guidance systems and the lead Su-57 aircraft ."
Suggests the lead Su-57 detects targets and passes target information to the drone which relays it to its weapons inside its weapons bay... the question is... is that enough to then launch the missile which then uses information from the Su-57 to find and lock the target, or does the S-70 lower the missile out of the weapon bay so it can use target data from the Su-57 to then scan for the target with the missile sensor to get a lock and then launch the missile?
I would suspect the former...
I think these are integration tests, no launch was performed. I don't know if some lock before launch were performed, in that case they would do as you say, but in normal conditions this will not be the case so it would not be really necessary. Seems likely that they just checked the communication between the missile and the avionics of the aircraft, form & fit and similar issues.
I would suspect these tests will be with lock on after launch missiles... R-77-1, R-74M2, R-37M, in which case they can test receiving target data and simulate engagements without launching missiles... data collected could determine if a lock would be possible and if the engagement would have been successful without launching a weapon.
Let's say that the armed drones, UAV and UCAV actually tested are almost uniquely subsonic so no one has EVER seriously tried to employ A2A missiles from them.
Now, the S-70 is advertized to be almost transonic so maybe they have just aiming to give it a try in such a role but I still think it would not be its primary one.
Having an S-70 drone flying at high altitude a little ahead of Su-57s would be a useful way of penetrating enemy air space... any enemy aircraft appear the S-70 could launch R-37Ms, while potentially fire R-77Ms at anything large launched at the Su-57 or themselves like SAMS or Meteors...
Having several of them means extra weapons in addition to primary weapons for the job at hand... Even when they use up their weapons they are extra sensors and EW jamming systems that can support you.