Hopefully the discussion was beneficial to more than just me.
deltabravo - I usually don't remove the mat except for an good cleaning. And last time I cleaned, I just flipped it to one side, cleaned, then flipped it the other side.
Yeti-plus - going from a Dodge Ram to a Ram and only change I'm aware of in the bed are the stupid plastic caps they but on the bed rails. Going from a 3/8" standard truck mat to a 3/4" rubber mat should be the only change required. But think I'll measure it today just to be sure.
Have ruled out the 2'x2' pieces because while they would be easier to remove, the joints would make it harder to slide items into the bed with the mat in place. Hope I can find a 4x8 stall mat, but seems they only carry the 3x6 around here.