Very sluggish paint brush

Please see the attached node tree. While looking at the output I am painting on the detail layer Paint 2. Any brush is extremely laggy and sluggish.
The culprit is not the Beauty Studio plugin, it is also sluggish just looking directly at the Paint tool.
Perhaps a problem with the Extract Detail node. But it should be cached and not have an effect on the Paint tool.
The image size is 1000x1200 - not really big.

Checking the RAM Silhouette is only using 1.3 GB out of 100GB free RAM. Is there a trick to convince Silhouette to use the available RAM?

P.S. Once I turn on ROI and move the region just a tiny bit suddenly the brush behaves normally.

It is expected that there would be sluggishness when viewing Beauty Studio or the Grain Comp when painting a stroke as additional operations need to occur to see the result in the downstream node.

Extract Detail caches the result so you will not see a delay when viewing and editing the Paint nodes–at least it is not on my machine.