The narrow belt indeed frees up the drive train a lot. I have yet to buy the set, but I found that mounting the rear upper tensioner above the deck and putting the roller completely to the front also helps. To mount the tensioner from below you'll have to take a 2.5 mm socket head M3 screw as the button head is too large. My front upper link mounts have bee fine so far, maybe because I put some grub screws into the empty mounting holes.
How did the LMR/MR33 flex deck work out for you? Everyone I asked so far liked it a lot. I'll be adding most of the bling at some point for sure, but for the time being I've got to focus on reviewing a bunch of 2WD kits. So many new toys on the horizon!