Custom capabilities accumulation

#1

Do custom capabilities accumulate?

eg - a subscription has a,b,c custom capabilities
the subscriber then subscribes to d,e,f ccap the following month

do they now have a,b,c,d,e,f ccap?

Thanks

#2

It seems so. There does not seem to be any process to remove/replace them. If a subscription ends, it might remove EVERYTHING, including the ccaps that are not associated with the membership (like a buy now).