I can see this as very useful feature.. Not only preset compression level at ACP but also to limit maximum resolution. I agree with AstonJ that it is not needed to keep maximum resolution in archive.. Maybe to recompress files after some time and only files with kilobyte size exceeding some level.
Actually some PNGs make sense - for screengrabbing for example… (it wouldn’t do any good to convert screengrabbed PNGs to JPG).
But I think we should focus on JPEGs where we can be very efficient and save space.