Fix | After spending a ton of time testing, enhanced controls now work for 1.16 clients. The fix uses ViaVersion to determine the client protocol and enforces another set of checks when pressing the shift key if the client is 1.16 or above. Slight jitter occurs when the shift key is pressed as the plugin has to remount the player once they release the shift key.
Please note that this is not perfect and can break if spamming the shift key hard for extended periods of time, however, additional constraints are enforced on 1.16 clients such as no movement so even if a player is desynced they can't do anything and will be re-synced within a few ticks or when they press the shift key again.
Let me know if this update causes any issues and I'll be sure to take a look at it.