Andrea,
Ahem, sorry for the incompetence but how do you avoid booting ladspa
and lv2 plugins?

Actually it is my incompetence -- you can not avoid ladspa but you can avoid lv2.  In Settings -> Preferences, Interface tab, there is a field Default LV2 plugins path.  Record what it is currently set to and then change to:    $CIN_DAT/lv2    it automatically re-initializes.    When done put back the original.