With both the versions there are similar performances behavior. DXO 4 behave as DXO 7 under the same conditions. If you copy and paste settings, after some image the system gets so slow that you have to start with the settings from the scratch. Having a quite large number of pictures, (e.g. 700) after the first half DXO become very slow even in moving between pictures scrolling the picture preview bar at the bottom of the screen. Masks are working very bad as well as image rendering. OS is Sonoma 14.5 MAC M1.
For many years now, PhotoLab has not excelled in scaling very well. 
I’s good practice to limit the number of files per folder to speed things up. 700 seems to be beyond what DPL can handle gracefully on your Mac.
Also, database inconsistencies can spoil the fun, but try with smaller folders as a start, and make sure you move images to other folders within DPL’s Library view. You can create new folders with the Finder, but touch them in DPL or it will not move the files.
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