My piece of experience: as you can see my Upwork history is almost flawless and i very rarely make big mistakes. Messing with Flutter was one of them. Happily i am Top Rated and can delete feedbacks, or i would've been in a big trouble.
I really recommend keeping away from that creepy framework. It just takes an extraodirinary amount of effort to get anything done in it at all, customers normally just don't bear with that level of productivity (something like Ionic will give you literally an order of magnitude faster output)
