I found out today:
If you use your own domain as verification, it is not necessary to put a _ in "names". Just leave "names" empty, then the _ won't appear in front of the @ in some clients.
cc jb55 (npub1xts…kk5s) Evan (npub18jg…c5gt) PABLOF7z (npub1l2v…ajft) Vitor Pamplona (npub1gcx…nj5z)