Memory leaks, memory management

I open this issue because I can't reopen https://github.com/aframevr/aframe/issues/3779, closed although there are some serious issues which are not addressed.

A fix is still needed to manage Context lost, which can have various reasons, not only models unloading/loading (see above for another one, maybe others exist).

Regarding the models loading/unloading : pooling is not sufficient if you have many models. You have a limited quantity of RAM available at any given point in time, so you have to dynamically load only what you need right now and unload the rest. As mentionned here, I posted some more in depth analysis about this here. TLDR : I'm using a workaround for the time being, which is unfortunately failing to fully release the memory, so my app is still being exposed to memory overflow.

Also, in a SPA, when you navigate between pages all having their own scene, each scene is destroyed/created each time, as the instance they live in is created/destroyed dynamically, so the idea of keeping the same scene throughout the user experience doesn't work.

So far, I really enjoy programming with A-Frame but to me, memory management is the really big downside that makes the engine unreliable for building ambitious projects. Really hoping for enhancements.

Start by reviewing the prior issue #3779 and the reported cases around WebGL context loss, model loading and unloading, and scenes being destroyed and recreated in a SPA. Done would require a defined approach that prevents the reported memory leaks and handles context loss reliably, but the issue does not name files or tests.