Personally I’d go with an UAR version, getting more image top and bottom and colors from the TV, while retaining higher resolution from BD; and if you can ehnance the lower quality source with noise reduction, grain, AI upscaling etc. and also pre-colormatching, result may be rewarding IMHO!
The only problem is that you need to use Avisynth, the process could be tedious as sometimes you have to manually correct the image matching or choose different settings for different reels/scenes/shots, and may take long time converting it depending on the hardware.
Quick example (no DNR, grain, AI upscaling etc.):
Needed plugin: Auto Overlay