Reimplement cache isolation as a direct C++ patch
Our current cache isolation relies on a cacheKey hack to isolate the content cache per domain. This requires an on-modify-request observer in javascript that could be done in C++ instead.
We should implement something that sets this property directly in C++. Or perhaps we should see if we can leverage the new concurrent Private Browsing mode code to isolate both the image and content cache with much less complexity than our current patches.
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information