If I remember correctly, one could use EMH on check-in and check-out days. Is it safe to assume this will be the case for the new early entry system as well?
I would make that assumption since you are allowed to check your bags w/ bell services and enjoy a resort, in full w/ all benefits, on check in day.
Should be able to, yes!
Disney counts the day of your check in and your check out as full days, so all perks for resort guests apply.