Just discovered Macrium reflect rescue media supports Bitlocker drives if you tick the right boxes when building the media. I had just done a backup to my Crucial X6 and was checking it with rescue media but the media couldn't see the bitlocked portable.
After DuckDuckGo search I discovered that rescue media needs the advanced section with bitlocker support in the PE environment. Only discovered this just as I was decrypting the X6 drive which is a time consuming and non reversible process unless you wait another 3 hours to encrypt the drive again.
Dont think I will bother with Bitlocker, seems more trouble than it is worth.