My S went to a few accepted student days and found them helpful in making his final decision. Some were definitely better than others – but in general accepted student days were more in depth than regular visit days (two had an overnight component).
It may be worth seeing if you can find the agenda/schedule for accepted students day at Case to determine if it is worth the scheduling difficulty. If you can’t make it to accepted students day it is fine – in that case I’d have your child contact admissions to see if they can arrange an alternate way to have an in-depth visit (perhaps shadowing a student for a day).
FWIW my D applied to her college ED and committed before accepted student day. She did her “due diligence” to feel confident of the fit through regular visits, shadowing a student for a day (she arranged it with admissions), interviewing with an admission officer etc. She did go to accepted students day to meet some kids she connected with online and to look at the freshman dorm options.