If there is really a need for that special unsupported plugin, then the best way to go would be that at least one of all those distributions, who currently maintains that plugin, "republishes" it somewhere (AFAIR projects.vdr-developer.org was invented for that?).
First step could be to apply all those patches that are required to get the plugin to work with current VDR *developer* versions.
If a plugin really is still needed by a bigger group of people, then it definitively needs to be maintained at some *central* place. It doesn't help if every distribution creates their own patches. It's much better to cooperate!
We are talking about > 100 Plugins. Maybe we can drop the half of these but > 50 will be remaining ...