I just wanted to report back for anyone else in the same boat.
After adding all modules that sounded relevant to Bitlocker, and their pre-requisite modules, and language packs (as found referenced on this pagehttps://docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/winpe-add-packages--optional-components-reference) to a customized ISO of WinPE, I was able to run manage-bde with unlock pw, and then decrypt the drive with manage-bde off.
Frankly I don't understand why the default Bitlocker recovery can't decrypt a drive from the password considering Microsoft themselves offer this public package capable of the procedure. It really offers no additional security.
Thanks to everyone in this thread who offered their advice!