Import function library jsx automatically
The ability to import a jsx file with a library of expressions is a great feature. I think it could be improved if there was a file somewhere in the Adobe preferences folder called something like UserFunctions.jsx, which is automatically imported into the After Effects namespace. This would allow users to edit this file and be able to access these functions without needing to manually import the jsx for each project. So if the UserFunctions.jsx contains a function called overshoot(foo, bar) for example, the user can just type overshoot(3, 1) into any expression and it will work. Maybe for safety they can be called using something like User.overshoot(3, 1) or something like that.
Colin Harvie commented
I second this. Being able to import expression frunctiosn from a library now is fantastic, but writing out "footage("lib.jsx").sourceData.myMethod()" everytime is still less than ideal. Being able to import functions in to the expression's scope would be fantastic.