Georg there's a bug with your modification:
When trying to retrieve slaves from the Retreat all my random named ones (but even Zenobia and Akari too) from the last row are renamed as the gladiator slave and given the image of one of the named slaves from the last row.
The way I got around it was to first retrieve the named main game slaves from last row and the last one from the penultimate row (the out of bounds one), then retrieve these random ones.
I'm gonna just put them into first and second rows. Maybe that would "preserve" them.
EDIT: Tested a bit more and the same happens with main game named ones on the last row. This is a problem...
I think only the last 4 slots have something wrong with them.
Here's a save with bug working (try retrieving Zenobia, Akari or the random named one):
View attachment slaveMORESPACE005.save
OT:
Btw, there's still not enough space for all the slaves (even excluding any random market ones, which I have none). I still have 3 slaves in the captured slots (the "sex slave" with the viking named bandits from Kasey, the lone "bandit girl", the japanese Talika girl that was with that japanese guy from the bounty) and if I process them will fill all the slots in the household too, with still 2 more slaves from the Slave Market gallery (Caitlin and May-Lynn) that have nowhere to fit. I guess I could marry one and put the gladiator slave chick in the arena (with no way to retrieve her).
The random ones I have in the retreat are:
Lucky, Urchin, Valkyria, the arab named slave girl that is given along with Aisha, the "cyber girl" that was with some cyber punks and lastly the gladiator girl (excluding Mae, Zenobia and Akari).
So yeah 2 more slots at minimum are needed. One idea is to have 2 more copy-paste Retreat pages (the original 9 slot one) and thus make The Retreat into 3 storey building with 27 slots total.
