I just installed my BAK MX4 w/RO brackets on my 2021 Ram 1500 w/MFT. Per the original post, he is spot on with the cuts and I didn't have to move the drain at all. The top rail fits flush with the rail liner, the tail-gate closes snug so we'll see if any adjustments are needed as it wears in and if the additional weather stripping is needed. I loosened the bolts a bit to lower the brackets, moved the front rail hold-down clamp as far forward as possible, the rear 6" from the tail-gate and the middle one centered between them. Unless BAK Industries makes a rail that is already cut to work w/ RO brackets( raising the holes a bit would lower the bracket so you wouldn't have to cut as much off the inside rail leaving a bit more support) for the MFT, you'll have break out the angle grinder w/cut-off wheel.