I've read somewhere that this feature is already on the roadmap, but I was unable to find it.
I have done a quick implementation of it on my ispcp installation. It consists mostly of code duplicated from the subdomain source, but it works pretty well on my machine.
I have attached the needed files to this post. Just apply the patch and copy the "ispcp-alssub-mngr" into the engine directory and "delete_alssub.php" in gui/client.
I think for a final implementation of this we should consider redesigning the manager code of all the managers a bit. There is lots of duplicated code that could be put in another common file.
alssub.zip (Size: 11.05 KB / Downloads: 51)