Originally Posted by
csport
Juin Tech M1 or
Motoko MTB are cable actuated hydraulic brakes for MTB. Not exactly cheap, but more or less do what you asked for: the two pads can extend by a different amount.
Make sense for road levers (I think it was
katsup whose post prompted me to upgrade to Juin Tech R1), for MTB you can probably just go full hydraulic.
Since we are mentioning Klampers, it probably makes sense to mention Juin Tech M1 as well
Those Juin Tech R1s are still working great on my commuter. They have a little over 4500 miles on them now. They work much better than BB7s in a drop bar setup as they helped with the lever pull when I was mending a broken wrist. I didn't think of them as OP wanted the ability to adjust pads separately vs combined, but they are a good option.
Another option that is rather new is from Growtac, which got good reviews, but are also expensive. Pass Less Pedaled did a video comparing them to Klamper and Juin Tech (Yokozuna), but his verdict was basically all are good.