I wanted to add to this topic with an example as I just experienced this!

Aspen with 80 SLVL (has had three interactions so she has 30 from that)


If I add this Blue Safe (the one on C3, doesn't matter where I put it), the SLVL goes down by 3.


Her SLVL does go back to 80 if I remove the C3 safe. I also tried removing other items to see if they would cause her SLVL to go up, but it all resulted in it going down. Adding additional items that aren't that safe also cause the SLVL to go down. So maybe there is an unseen, intentional item limit or this isn't intended?