Right, they are DLL's registered uniquely, I didn't mean to infer that they were identical. But, ultimately, they are functionally the same from the user perspective of a black box that has ins, outs, and configuration parameters.
A migration path should be possible in the host. The host could even do the export of the old parameters (it has them), ask you for the new replacement plug-in, then do the import of what it exported, and if there are no errors then remember those steps for future use un-prompted where it just converts automatically.
Yes, and they could do all this just to make the center of the known universe happy ... Ha ha ... ;-)