OK the solutions should be very easy.
Under the MIDI In plugin include the filter plugin and filter the note on message.
Then bypass this filter plugin, so you can get the note on message.
When you activate the filter then note on message is filtered out, but the note off message still gets through.
Do not bypass the MIDI IN Plugin itselft, use a filter.
You could also map a widget to the filter note on message built in the MIDI IN Plugin itself.
This way you simulate a “patch persist” with variations.