It’s not too hard to go from airlines to biz av, it is comparatively much harder to go to airlines from biz. Personally for a bunch of reasons I would recommend airlines as the place to learn. It’s safer, training standards are higher and if you decide you like it - you can’t stay or if you still have the desire for biz, then you can still go that way. It’s the least risk to your career.
if on the other hand you’ve made up your mind, then ignore me and be you.
for context, I flew 18 months in a terrible turboprop outfit “airline” then went biz and never looked back. Airlines just ain’t for me, I love managing the craziness and the level of autonomy that I couldn’t get in an airline. That being said I much prefer the safety and training in a bigger company like NJE, which is why I’m happy here.