I cut up my bed rug from previous truck (ford raptor) and it works pretty well and only slightly janky. Also used the tailgate section in the gear tunnel which really helps prevent things from sliding around. Sent a message to bed rug and sounds like the have solution for R1T in development.
Looks like bed rug has one in development. I am long time bed rug owner and sad to see there is not currently a solution other than cutting one to fit, which I plan to do while I wait on bed rug.