The number of keys doesn't matter. You would have the seeds for every associated key, and would therefore be able to easily import into another wallet.
Don’t wait to find out, build a nostr:npub17tyke9lkgxd98ruyeul6wt3pj3s9uxzgp9hxu5tsenjmweue6sqq4y3mgl
Also you need more than just the three keys
The number of keys doesn't matter. You would have the seeds for every associated key, and would therefore be able to easily import into another wallet.
What about wallet configuration details or derivation paths? What if you lose one of the keys?