Trade in that 12" bucket for a 16", we have clay here and my dealer recommended I not go with the 12" because they get complaints about the clay sticking and not falling out of the bucket. The 16" is about the right size where there's enough weight for it to fall out and I have had no issues. It does get roots and clay stuck in the BH teeth, I had to floss it the other day with a shovel. I'm right at 46 hours on my
B2920 and have dug about 20 stumps with it so far, the 16" is a root ripper. The largest stump so far was a 30 inch diameter Fir tree, that mother had roots the size of some stumps. Yeah that stump is still sitting in the ground waiting for the stump grinder no way this tractor was going to move that thing its huge but I was able to rip out all its roots.
Pro tip - if you get in the habit of moving your chainsaw and gear around in the FEL bucket remember to take it out before digging in a dirt pile :duh: