i have been doing some research and i still need to do more. but from what i have been reading, my take away is that the bleed procedure has a lot of do with the success of your tbu swap. if you stave the MC, it eventually ends up starving the abs unit, which can be a pain to bleed (from what ive read, also common on other toyotas).

a fair amount of the people who arent satisfied with the swap claim they werent happy with the pedal feel and went back to stock; most of these i come across on this forum do not further elaborate.

the measurements on the first link you showed me do in fact confirm the tundra caliper is bigger overall (but not by much). which would likely mean that there is slightly more passage length for the fluid to reach the piston; although i wouldn't think this would require a larger MC. these calipers really arent that much larger and you arent jumping up in pistons either.

sorry for not multi quoting. it doesnt seem to work on this forum.