Recent updates have broken this extension, yes even the update as of 01-18-2022. The memory leak is still in effect as is the CPU use cycles. The only difference I can see is that the firefox.exe that is hammering the RAM will now close when closing the browser (before you had to kill it in the task manager.) This extension's high resource use is enough that I am considering it potential malware.

Update. After uninstalling and reinstalling the ap, the memory leak seems to be resolved, as is the CPU thrashing. The mod once again seems to be functional, I will increase the rating of this addon if it continues to work as designed for a few more days.