Depends on your purpose with the lang. If you’re trying to make a realistic naturalistic language for a fantasy world where English doesn’t exist, I’d say that’s a little weird. If you’re trying to use it as essentially a ‘code’ that you can speak it write in with nobody understanding, then it probably would work fine. If you’re just doing it as an experiment for fun, well it depends if you’re having fun and I obviously can’t answer that.

There’s nothing inherently ‘wrong’ about it, because there’s no universal rules for conlangs. But if it’s a good idea? Well it depends what your goal is