I've been using this as my pubkey.
...can I just switch to the npub version of that, without confusing apps and relays and followers?
I think my npub is/would-be : npub144d2kklgswjhr63hkgcumxtdxafzua7s7ysuah7k0paerkzgy68qurzyy7
I used @rot13maxi's tool just now.
It's valid when I enter it on my end. Make sure there's no whitespace or anything extra in the field.
And yes, the npub is just a difference encoding.