I have an effect plugin and a tester of mine has reported an issue with VST3 whose tail gets cut off after about 12s of no actual signal passing through.
Update:
I missed to report that changing the condition didn’t make a difference in Cubase specifically, but I am not sure how other hosts would react. Very weird that no one has hit this for 4 years…
BTW, in Cubase this can be disabled: Preferences/VST/Plug-Ins and uncheck “Suspend VST3 plug-in processing when no audio signal are received”. But if the implementation for tail is incorrect and the host doesn’t allow it, there is still an issue.
Mind you - this isn’t foolproof. Cubase will only list your plug-in in the first category you supply. Other hosts, such as REAPER, will list your plug-in in multiple places.