This type of experience sharing is interesting, but only really useful to someone with very similar conditions. If someone is a “WFH” customer service rep who is expected to be manning the phones from 9-5 New York time, then I imagine it would indeed be very tough to work those hours while living in SEA.
Personally I do most of my work when it suits me, it’s only scheduled meetings that can be inconvenient.
This is probably not the right place for such a question.
But I am a developer, and this part here:
It’s not a realistic concern. Or rather, if your idea is so good that this is a realistic concern, you should learn how to develop the app yourself. But I really, really doubt that is the case. Generally, ideas are worthless if you can’t execute. Presumably your idea relies at least somewhat on your knowledge about psychology, and probably other knowledge/skills you have that a dev won’t have.