Describe the feature you have in mind.

Add a setting in the config file to turn the jetpack's ability to boost elytra on and off

Does this solve a particular problem?

Yes, it balances elytra in packs where there are mods such as aileron which disable elytra's ability to use rockets https://www.curseforge.com/minecraft/mc-mods/aileron

I have added an option to the server config in the lastest version