Alternative flying options for accessibility (toggle and fly window)

I really appreciate the new setting in the snapshot update which allows you to increase the window for double tapping forward to sprint! It works amazingly for me as I have cerebral palsy, which makes it difficult to repeat movements quickly for things like double tapping. It would be great if we could have this feature for flying too, to allow people who struggle with fast movements to enable flying with a slower double tap.

However, not everyone can do repetitive movements like double tapping at all. When I first played I had to call over a parent every time I wanted to fly because I wasn't able to do it myself. 

With this in mind, it would be amazing if we could have two new accessibility features:

An adjustable fly window setting, almost identical to the sprint window setting

The ability to toggle fly by pressing a single key, similar to how you open and close your inventory