You can still respond on the local feed, but if you want your posts to show up there for others to see then you need to use a henhouse NIP-05: 
You can own multiple NIP-05 ids, but only one can be applied to your profile at once, so yes it will also change it on other clients.
ps. Welcome! 👋
Henhouse
Henhouse
A Nostr Relay + Client for Women
