I tried looking through old responses first, but I couldn't find any questions directly related to the topic of the accuracy of the oppressive spanish mission.
I have a follow-up question to help understand the Missions in general:
Are they examples of reducciones? I've never seen them called that and never understood why.
I just gave a long response to u/dauthie that may answer some of your questions. If you're interested in the particulars of the forced labor, surveillance activities, corporal punishment, etc., I can address that as well.