I suppose that when Audacity 2.0 is released all of the 1.3.x versions will be officially obsolete so “version 3” plug-ins can be simply labelled as “Requires Audacity 2.0 or later”?
Yes, but the question is: Will Audacity_2.0 come in this life or in next life? Since approx. five years I read “Audacity_2.0 will come soon”.
If it is going to be a long time before Audacity 2.0 I think that we need some way to differentiate between plug-ins that require recent Nyquist features and those that work on any Audacity 1.3.x version.
Perhaps there should be “version 4” for plug-ins that use (get-env), back slashes in string widgets, (notch2) on stereo tracks and other recent features.