My studio is based around the 404 mk2 feeding into my DT and I can confirm its very good fun. Tons of possibilities for how the two can interact but I’ve found the best inspiration comes when I chop up and flip samples on the 404 using the resample method then time stretch those loops on the DT.
The 404 by itself falls short of being a proper live looper/remixer like the OT but if you adjust your expectations its quite good. Paired with the DT the 404 is like adding the fun part of the MPC to the DT workflow without all the extra MPC junk.