Is your feature request related to a problem? Please describes.
When I play hypixel skyblock dungeons players have glowing effects and that slightly lowers the fps

Describe the solution you'd like
Optimizing the glowing effect

Describe alternatives you've considered
Buy me a pc and play at over 60 fps

Additional context

Not sure on what configurations it happens exactly but it's terrible on Windows 10/11 and Intel HD 4600. And it's fine on Linux/Windows and Intel HD 4000. Looking at #801 it's bad on macOS and Radeon Pro 560 too.
Not only it drops FPS but it also creates weird cursor/camera rotation lag that looks like "throttling" and I have also noticed that OptiFine's Smooth FPS fixes rotation lag but drops fps in half when seeing something with the glow effect.

Maybe for now it would be a good idea to just implement a simple toggle that completely disables this effect?

I obtained 37% higher fps with 445 entities with glowing with 2967d1a

Maybe for now it would be a good idea to just implement a simple toggle that completely disables this effect?

Not sure, since this breaks the whole essence of the glow effect. But you can try other mods like No Glowing

I like your alternative option