I tried to find this answer on the forums but I could not so here it is.

What would be a proper way to set up a PDG rendering exrs where it can identify and skip existing frames?

I know that for caches PDF identifies automatically what is on disk but the same does not happen with images and I could not find anyway to do it.

Any tips?

I think I figure it out.

-Turn off "All Frames in one batch" - it seems this options ignore totally what is already written to the disk.
-If you want to render all in one batch and detect/ignore what is already on disk dot it on the scheduler, on the job parms set it as "single".
-In the ROP Fetch output files tab use "custom path list" and add here the path where the files should be.

This seems to be working for me so far so far, if anyone have a better way let me know