Sparrow, Nunchuk, and few more soon. Doesn't take many wide install clients/signers to be enough. Take a closer look, a lot good stuff there. SeedHammer guys also working on an Output Descriptor spec for bbqr.
BCUR is no go, terrible for hardware, lots of dependencies, over complicated for no reason, poor compression, was first mover, but doubt it will be the main standard in the future.