I was thinking with Linux the Biab Track Injector should work and inject the wma if the Linux version of Reaper handles wma files now ? The Win version used to use ffmpeg but that was not accurate so they used the WMF codec after I asked them.
Though it will handle any other format you convert the RT RD to like mp3, flac, wav, ogg, wavepack, aiff.
It would just need the paths in the script changed to add the wine drive to the path for bb and AutoHotkey.