Worth noting that the Shimano brake changed massively around the M666 and a lot of the ‘information’ about bleeding them relates to the old design. M675,M785 and 8000 XT should be bled per the instructions in the box with the bleed funnel, which turn out to be exactly the recommendation from Epic also.
The only additional points of note are that the bite screw on the XT’s needs to be open and that many like to add an extra stage at the end with pads in and disc spacer to effectively overfill the brake and make the lever bitier and less progressive although this effectively wrecks a lot of Shimano’s work in design.
The very best tip on them though is a one liner buried in the Shimano instructions to the effect that if there seems to be air trapped you just can’t shift, check everything is done up, empty the system and start from scratch as if you just put a new line on. It’s a big time saver.