So, I've found an easy way to make the vendors regenerate their stock, you only have to leave the barter window not dialog but the barter window will take longer to load. 6-7 seconds for me when I tried it just now.
I made a copy of the Trade in the Story Editor and in my copy I changed line 114 and line 140.
PROC
GenTradeItems((CHARACTER)_Player,(CHARACTER)_Trader)
AND
DB_TraderGeneratedTreasureForLevel(_Trader,_OldLevel)
AND
CharacterGetLevel(_Player,_NewLevel)
AND
_NewLevel > _OldLevelTHEN
NOT DB_TraderGeneratedTreasureForLevel(_Trader,_OldLevel);
DB_TraderGeneratedTreasureForLevel(_Trader,_NewLevel);
DoGenTradeItems(_Player,_Trader);
to
_NewLevel >= _OldLevel
And also
PROC
GenTradeItems((CHARACTER)_Player,(CHARACTER)_Trader)
AND
NOT _Trader.DoesNotWantToTrade()
AND
LastTradeItemGeneration(_Trader,(INTEGER)_THLastGen)
AND
_THLastGen != 0
AND // check if last generation was long enough ago:
Time(_,_,_TH)
AND
IntegerSubtract(_TH,_THLastGen,_Delta)
AND
_Delta >= 48THEN
DoGenTradeItems(_Player,_Trader);
to
_Delta >= 0I haven't looked into how to properly build and publish a mod yet though. I took Rhidians purchasable skill books and added my changes there just to try it out. If someone wanna make a module and share it with the world I'd only be grateful.
EDIT: Successfully made a mod after all:
https://www.dropbox.com/s/9s9snwsogeasitx/ARTI.zip