Took a stab at implementing an override of GetVirtualFileSources method with minifiers, and noticed that the method is called twice on startup. On the second call, the memfs that is injected is not in the list that was modified in the first pass.
It works, just that when it is called the 2nd time, the memfs that was added to the list in the 1st pass isn’t there, so all the html/css/js files are re-scanned and processed. Little bit time consuming.