I think this is much closer to the right way clients should interact with relays they connect to.

NIP-65 is outwards facing; is to announce to others how to communicate with you; but this is a separate thing of what relays you want a specific client to connect to.

NIP-65 even explicitly says so.

I think Relay Sets as defined in NIP-51 can be A way of grouping this relays you want a client to connect to

“Connect to my ‘work’ relay set”

“Connect to my ‘gardening’ relay set”