Looking for a Plex/Roku Profile for Direct Play

Howdy, I’ve tried reading through the custom profiles but it makes no sense to me. I simply want MKV H.264 with AAC. The MKV Normal uses AC3 which leaves a transcode job to bring it to AAC. I’ve manually converted files from Plex DVR saved as TS with great results.

Is there already an existing profile using my container format? I don’t want MP4 so I have stayed away from the pre-built Roku profiles.