The LV2 FHS that Jeremy mention can be found at https://lv2plug.in/pages/filesystem-hierarchy-standard.html
Now you may not like, or disagree with the official standard, but breaking it is not acceptable. This affects various 3rd party software, notably Reaper, Harrison Mixbus, Ardour and other non-free DAWs that expect LV2 plugins in /usr/lib/lv2/
LV2s are to be installed $PREFIX/lib/lv2 (unrelated to $LIBDIR). Most LV2 plugin build systems use LV2DIR = $PREFIX/lib/lv2 for this. Thanks in advance, robinPS. VST3 has a similar spec using /usr/lib/vst3/ - https://steinbergmedia.github.io/vst3_dev_portal/pages/Technical+Documentation/Locations+Format/Plugin+Locations.html
OpenPGP_signature.asc
Description: OpenPGP digital signature