Unloading specific texture-streaming data from maps

Hi! I’m working on a project which requires me to load thousands of textures for frames in runtime (25fps). while the approach to show/hide them works just fine, the amount of cached/streamed texture data crashes my project (“Out of video memory trying to allocate a rendering resource.”). I already tried to use level-streaming with sublevels to create small packages of 100 frames within each level. I am loading them into the “real” level where they will be shown and I am unloading the last 100 frames. Still the cached/streamed data remains in my storage and keeps on growing with each new set of frames until the engine crashes. I used this approach to avoid needing to rebuild my project with C++ (which I barely know). Is there a way to access specific saved texture data and delete it?

There have been similar posts before, but no solution has been given yet.
A Post from 2015: https://answers.unrealengine.com/questions/308513/emptying-the-level-doesnt-free-memory-nor-restores.html
“The bug entered is UE-21800. It has been verified and fixed as number of fixes were entered into recent versions that address the issues mentioned here.” - Since I’m working in 4.18.2 it just doesn’t seem to be true that this bug has been fixed! Inceasing th Pool size only helps temporarily if at all i the number of textures is very high.

Links to older posts with the same problem:

I found this thread with an answer from mighty RAMA further down but it seems to be in C++. Is this the only solution? Unloading Assets to Free RAM? - Platform & Builds - Unreal Engine Forums