Unless I already told you privately, you might not be aware of an undocumented (well, at least before today) option to adjust DprojSplitter to your needs.
By default DprojSplitter splits the following entries in each PropertyGroup of a dproj file:
If you want to modify or extend this list, you have to provide a configuration file for DprojSplitter with a list of all PropertyGroup entries to be split. The file has to be named DprojSplitter.cfg and has to reside in the IDE AppData folder (which is %AppData%\Roaming\Embarcadero\BDS\19.0\ for Tokyo, adjust the number to your IDE version). The file should contain one entry name per line.
Be aware that such a file will override the default list shown above. So better make sure to include that list in your file unless you explicitly don’t want some or all of those entries to be split.
F.i., if you want the DCU output folder be split, you have to add DCC_DcuOutput to the above list.