I have played around with speed and throttle control to help reduce vibration feed back into the machine. I contacted a guy locally who had run the bobcat packer a bunch and he mentioned the same things. The bolts snapping and coming loose could be associated with the vibration going into the machine. The material I have been packing has mostly been 3/4 crushed gravel on driveways and it is pretty obvious when it is compacted but not always. I did one driveway where I added 3" of 3/4" crushed limestone and it looked packed, but was giving a lot of machine feedback regardless of throttle or speed. When I drove my truck down the driveway it left ruts.
I also had a number of bolts come loose in a short order, and wouldn't stay tight during this job.
The guys at the Bobcat dealer took 4+ hours with 2 guys to put it on the first time and the second time it took even longer. The first time I did it by myself, it took me 6 total. The biggest issue is the blocks that the plates mount to. After struggling with lining up the holes, I took it all apart and found that the blocks were not exactly the same length. (Varied up to 1/8" in length) This would put the holes out of alignment. So I spent some time lining up the holes in the little blocks and that made it better, but there was still some fudging and one block would not fit no matter what way I put it in. I have seriously debated welding it. Will consider that more so after I am out of warrantee.
I know that moisture content has a large effect on it as well. Thinner layers with already compacted material underneath seems to be the hardest to find the correct speed/throttle combo to prevent feedback.
It is winter here now, so not much use going on with it now. I have found most of my Bobcat implements well designed and built. Hope this isn't any different.
Equip