Is your feature request related to a problem? Please describe.
Having magma enabled makes scrolling slow, especially in larger cells and files.

Describe the solution you'd like
I didn't have time to look into it in more depth, but MagmaUpdateInterface should be made as performant as possible, maybe caching and only moving certain elements, or not be called on every curser move event. Doing slow computations asynchronous might also be possible.

Describe alternatives you've considered
Simply disable the autocmd.

Additional context
I'll probably be able to look into it a little at the end of next week.