Don't think this is a big issue but I found an error when attempting a photoshoot when one of the girls is unavailable when they're in the spa for relaxation.
I think this is because there is no construct for the variable sparelax and therefore has no name or shift associated with it. Was able to work around this two ways in case anyone else had this error.
The first one was by making a separate construct for sparelax. After line 6125 you can add the following to add a construct for sparelax:
While this does work it will still say they're unavailable due to working at the spa, which while not true you would have to edit the code for the photobooth further which isn't really necessary.
The second way is by just removing the code that specifies where the girls are working when they're unavailable as it will no longer check the shift or name for sparelax and therefore you won't get the error. You can do this by erasing this code in a text editor:
Hope this was helpful to anyone and I know there are multiple other ways to address this error but these were just my suggestions for the easiest ways to do so.
PS: Saw an issue with the second way later in the game. Will see if I can change it later as it made Charlotte unavailable even when she wasn't working.
PSS: Changed the method for the second way to only require deleting a portion of code.