How do Uhu IR searchlights work?

I'm looking at a few things that I'd like to be able to do:

1) Have other units be able to target the units revealed through FoW
2) Have the 251 Uhu be able to "lock" it's beam on a target entity by either right clicking or using a searchlight rotational toggle
3) Add an 360 degree aura that simulates the IR 251's scanner on infantry squads with IR StG Vampirs.

So far, I looked at the Valentine and it has a weapon_scan action, but it doesn't seem to be able to accommodate what I would like. I've then looked into the 251 Uhu and was unable to find any reference of scanning whatsoever. I'd like to better understand how the Uhu manages it's searchlight, and ultimately figure out if any the things I mentioned above possible.

The IRHT searchlights scan_action is under the unit's sbps file.

The modifier that the scan action applies on reveals units in the FoW, but doesn't allow units to acquire the target.

In order to allow revealed units to be targeted, you would probably want to use something like Command Panther marking (which actually reveals the territory beneath the affected units). Doing so has the potential side-effect of allowing players to target off-maps on revealed units (i.e., it would allow them to bypass FoW requirements).

Regarding (2), I've never tried anything similar. You'd have to experiment with it using IRHT's weapon (which you will find linked under the scan_action

Regarding (3), I'd go with something like Valentine, and an always-on action, or a toggle, or whatever you have in mind. Note that a scan of 360 degrees won't really be useful to the player, since they most likely want the area in front of them scanned (145 degrees), more than anything else. A scanner that rotates the full 360 degrees means that it's not detecting something useful at least 50% of the time (maybe that's the downside you're aiming for?).

Currently, there's a very serious bug regarding IRHT and Valentine. Any infantry unit that retreats while being suppressed at the same time of being scanned has the negative effects (maphax) permanently added of them. I've made multiple attempts to address this, but to no avail.

My recommendation to you is avoid putting severely hampering side-effects to the aura (e.g., making squads easier to hit), due to the potential for the effects stacking permanently.