My workaround was for SONOS 5.1 due to their lack of DTS (SUB, Playbar and 2 ONES).
In Kodi under audio options (make sure to set it to expert setup)
Set "number of channels" to 2.0. (some weird bug)
"Output configuration" to optimised.
"Enable Passthrough" on
"AC3 capable receiver" on
" - Enable Dolby Digital transcoding" on
"DTS capable receiver" off
- - - Updated - - -
I'd still prefer some form of passthrough and DD transcoding in Enigma2 if possible :) Happy with the workaround for now though
Ultimately SONOS should pull their finger out and support DTS