I use Romcenter for several Romsets and it is really hard work to change a set from Un-Merged to Split!
Cause if you do this with Romcenter, you have to create every Clone/zip by hand! It would be nice, if Romcenter could handle it! Creating ''Dummy'' Zip by using the Datfiles! So you can import easy, the specific files for the clones!
I wanted to reduce the size of my roms, cause i need some space for more roms

That results in erasing the roms of the clones in the parents and the lost of the clones!
And i think an option like ''Create Dummy Zipfile'' could handle this perfectly! So you can change from un-merged to split very easy!
If you want to change, romcenter scans the files, and could see that there are no Zips for the Splits and could create the files automatically! Then it copies the specific roms into the files/zips and delete the clones out of the parents!

I hope you can understand what i wanted to say, sry for the bad english mais mon français est aussi très mal!