
Was this the first version of that other one... "Easygoing territory defense by the optimistic lord: production magic turns a nameless village into the strongest fortified city"

no the other version of that story is:
https://www.mangago.zone/read-manga/okiraku_ryoushu_no_tanoshii_ryouchi_bouei/
Spoiler ch 18
The king spent days/weeks trying to find the source of the poison and interrogating the vendor (realizing only after a very long time that the lady could send someone to buy it and not go herself), then only after their lead into the source got silenced did he realize that "could Amelia be in danger?".... Was the fact that she was being sent poisonous letters not clear enough as a message? I'm going to have to drop this