Hang on... I'm no expert, but hot front left and rear rotors implies the SMC is working fine, but the front left caliper is dragging?
That could be corrosion, seals, pad pin... but that caliper dragging will activate the SMC, which will activate the rear caliper.
Unlikely to be a hydraulic cause - a front master cylinder/lines/etc issue would cause both front brakes to drag, same with the rear master cylinder.
I'd pull that front left caliper, remove the pads, and check for obvious dirt/corrosion. The pistons can be cleaned in situ (although awkward with all the brake lines connected), and once clean you should be able to push the pistons back into the caliper with your thumbs (careful not to let the master cylinder reservoir overflow). If you can't, that indicates that piston is stuck. Could be corrosion, perhaps a damaged/displaced seal. A seal kit should sort that, although the system will need bleeding after.
If the pistons are all fine, then the pads could be dragging due to damaged/dirty caliper pin, or perhaps getting hung up on the spring pads inside the caliper. Taking a good look should find the problem.
