Placing mercs at border is not my style, let me explain:
previous battle ended and the sector instantly popped up with no time to crouch/prone mercs
in their standard defense positions at ~ 25+ tiles from border.
(as usual i spent time to get a grip on view conditions and determine the best defense spots)
Spy was at least 20 tiles away from other mercs when enemies entered and spotted unprepared mercs, opened fire etc,
enough to drop diguise and get poor spy killed.
Solved it by reloading save while in previous battle, move order for unprepared mercs&cancel to get away from the border,
nevertheless a little annoying.

However i also got some weird behaviour of suspicion counter where it appeared to go erratic:
A) disguised merc in building near wall, enemy outside on adjacent tile,
during the following turns suspicion went up until disguise dropped,
only to automatically come up again next turn with pure yellow spyname.
similar for NW sam site of AR 1.10 but there the spy was moving prone in the southern building
next to&behind the outer wall with the windows facing SW, while enemies were outside the fenced area, ~15 tiles away.
I also switched to realtime and moved the merc repeatedly forth and back,
when passing behind the windows he became more and more suspicious and then redisguised a couple of times.

Soldier still standing at map border had 114 AP
when checking a save from 1st turn with alt+e in AR 1.10 @insane(= +5AP) and no deputy/squadleader in enemy team.

20 AP for looking through scope appears too high since scoped rifle takes less,

no additional 20 AP for other direction(unless prone)

and last not least reveals entities in vision filed instantly instead of next turn,
which btw leads to paradox that spotter may get killed by "invisible" person in front of him.

Perhaps split spotter job and merely looking through scope for info about battlefield in 2 different things
and either have the latter take less AP for each look or allow to keep looking when we change direction.