Actually the inclusion of LADSPA may be the answer, it looks like there’s a plugin in the SWH collection with similar intent to the noisegate nyquist filter I used in audacity.
https://wiki.audacityteam.org/wiki/Nyquist_Effect_Plug-ins#Noise_Gate <this is what I used
http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html#tth_sEc2.45 <SWH has 2 different gate filters that should perform similarly(they expose all the same options) but I don’t see in the existing audio filters unless they’ve been renamed?
https://www.techjunkie.com/remove-echo-audacity/ < suggested default settings for an echo reduction preset