Watchtowers- possible supply stations?

[Carle]

It occured to me that watchtowers might be converted to a "supply outpost" for supply trains and the like. The only reference to them in script is the "GeneralCapturesResidence" which can apparently refer to a fort or a watchtower...
it doesn't look possible, but maybe a preplaced watchtower/resource combo could do the trick?

[AJStoner]

I based my export_descr_character_traits file on the Broods, Bloodlines, & Bastards mod which had a trigger condition that the notes said was explicitly there to prevent the resupply triggers from working at forts. After removing them however, characters in forts still do not have their supply trait reset.

[Carle]

IIRC the BBB script uses a "notInsettlement" condition to ensure that it isn't in a fort. Watchtowers are different though, and in any event they are always buildable from my understanding...
That said, might a "resource" work as a substitute? IE a non-tradeable resource (value 0- prevents merchants from trying to use it and no income for the region) that would refer to the player's presence there.
That doesn't solve the problem of owning it, though. Perhaps if an army enters "enemy" or "neutral" lands, then they need to have an army/unit on there (it's a supply depot- you need to guard it!) and an enemy/hostile nation needs to kick you off it by conquest. Maybe paired with a perm "stone fort" "village" for raiding purposes.
So if you don't have a garrison there, then an enemy unit can swoop in and take it, starving you into submission. Allied regions (with military access?) would support your armies as well.

So...

monitor_event GeneralCaptureResidence (fort or watchtower apparently)
and FactionIsLocal
and OnResource (it requires character record, and no "fort" will be on any resources aside from the "supply depot")
and not RegionIsLocal (Hotseat?  it would only work for players, but still...)
and IsRegionOneOf (RegionX)
 
inc_event_counter supply?regionX 1
 
end_monitor

and

monitor_event GeneralCaptureResidence
and not FactionIsLocal
and OnResource
and I_EventCounter supplyregionx > 0
and isRegionOneOf RegionX
 
inc_event_counter supply_regionx -1
 
end_monitor

...for every desired fort/supply combination on the map.
..
Alternatively one could use "CharacterTurnEnd" and OnResource/NearTile...
maybe

monitor_event GeneralCaptureResidence (for faction A)
and FactionType FactionA
and IsRegionOneOf RegionX
and I_FactionNearTile FactionA d x z (of regionx)
inc_event_counter FactionARegionX 1
end_monitor
 
monitor_event GeneralCaptureResidence
and not FactionType FactionA
and IsRegionOneOf RegionX
and I_EventCounter FactionARegionX > 0
inc_event_counter FactionARegionX -1
end_monitor

... this would be a LONG process, plus the traits... though a single trait with numerous triggers might expedite it somewhat.