In addition to the above interference issue, I also don't see any way of retaining the axle bearings between the two side plates. These look like flanged bearings, in which case the easy fix would be to flip them around so that the flanges are inside the module instead.
Seeing how compact you've gotten this thing already, I am also led to consider the possibility of ditching the outer branch of the mecanum side of the module... Doing so would require screwing into the outer end of the axle to prevent the side plates from pulling apart from each other, but swapping out that bearing for an X-type (4-point contact) or conical bearing aught to do the trick. (The robot frame would support the opposite side panel, so you'd only need to swap out the one bearing.)
Regardless of whether or not you take that suggestion, however, this is looking pretty good! You've made a whole lot of progress in a pretty short time here.
