Do you have any issues with the board / shelf the Dillon is mounted to? No, as mentioned the Dillon is mounted threw two 5/16" flat steel bars you can see welded across the top of the frame and the RCBS to a similar plate. I size 45/70's in the RCBS and its rock solid. The Dillon is setup for 357 Mag.
The frame pic doesn't show them as this was a trial fit to determine where they needed to be positioned but there are 3 x 5/16" welded tabs against the rear wall with dyna bolts and one on the right side wall.
The actual top board takes no stress. Its just a platform for working off etc.
The cupboard sides and rear wall are also bolted to this frame as well as screwed together. The shelving unit is standalone with its own back panel and it is just panel pin nailed into the rear cupboard panel. So if I need to change the shelving or add more then its easy to pry off and redo accordingly but so far there is no need