Absolute_Dakka: Based on the description saying that the new expanded Inn allows a player to do everything they could do in camp in the maze, it would follow that being unable to cast DIOS on a party member to heal them is not intended behavior.

Tested on 3 different saves, 4 different characters. Confirmed all of them knew the spell, 3 of them were bishops and one was a priest. Nobody able to trigger the cast of DIOS after choosing: Inn > selecting character > inspect character > navigating to priest spells > confirming available castings > clicking the DIOS spell as well as mousing over and using Enter and Space bar. None of them was able to get the spell to cast on any of the characters from any of the save files.

Only a minute before, in the Dungeon, on my main save file, I had successfully healed using DIOS both in combat and in camp with all three bishops. (The priest sits in town).

Sandown2.0: I found with expanded on just resting any character healed them (as well as restoring spell points if they have them). There is an option to rest the whole party in the Inn UI. my gold did not change (bug or feature of the expanded mode?)