Just adding to this thread really:-
https://www.steinberg.net/forums/viewtopic.php?p=616078#p616078
The news that now SSL Native plugins, at the release of v6.2 are supporting this functionality for Pro Tools (which will no doubt soon migrate to Studio One, etc…). From their website:-
(SSL Native) V6.2 also includes the addition of Pro Tools gain reduction metering for the Bus Compressor, Channel Strip, X-Comp, X-Valvecomp, Vocalstrip and Drumstrip plug-ins…