Free parking for customers up to X hours?

How do I tag that a parking is:
Free for customers up to 2 hours, after that you pay
Non-customers need to pay

Bonus point: There’s probably a max-stay of 24 hours for all

Surely it should be:

fee = yes
fee:conditional = no @ (customers AND stay < 2 hours)
maxstay = 24 hours

i.e. there’s a fee for everyone, unless you’re a customer who’s staying less than 2 hours.

Since customers is an access value rather than an access key, probably something like:

fee:conditional = yes @ (stay > 2 hours); yes @ customers
maxstay=24 hours