The suggested changes that make each now a dwelling unit would include any requirements of a individual dwelling unit. Think about it as if you are making a Multifamily dwelling, can you or would you want the circuit breakers for the lights in one unit controlled by another unit, would that be compliant? (Take out consideration that this was at one point a motel.)
The only time I was in an extended stay was an old Marriotte that was a hotel and changed to an extended stay as you are suggesting, each room suite had it's own small panel. If I remember it had HVAC, stove, lights and receptacles.
Your quandary sounds like you now have a large change order from what was originally proposed, and is the owner prepared for it.
One loophole might be to add a circuit for a hotplate as opposed to actually perminant cooking appliance sidestepping Dwelling unit, but a lot of insurance companies frown on hot plates as they have been a significant fire hazard and cause of hotel fires, thus why you almost never find one in a hotel, and usually are listed as prohibited from being guest supplied.
