[mschnell]

I understand that the file tells Reaper how to handle a dedicated (VST- parameter -) value (according to a kind of parameter specification such as FX_EQ_BYPASS -> binary, FX_EQ_NOTCH_NAME -> string or FX_EQ_MASTER_GAIN -> continuous).

In some way such identification needs to come from the plugin. how else should Reaper know that a parameter it really is e.g. a " FX_EQ_MASTER_GAIN " ?

Hence if you want to use some new VST with some new parameter identification (whatever this is) same would need to be notified in the ReaperOSC to allow Reaper to use it in the dedicated way.

But I never did any work in that area, and especially I don't have any idea how the said parameter identification options are transferred from the plugin to the host.

Maybe you want to ask in the "developers" subforum.

-Michael