Have the same machine and have removed some fairly massive oak and southern yellow pine stumps with it and one of the tricks I have found with the roots is to not undermine them but to try and get the teeth just under and curl the bucket using the ground beneath to push against the root. It is a lot less jarring on the machine and myself and the bucket curl generates much more force than the boom or stick. If I cannot break the root then I will move a bucket width further or so away from the stump and try again. Some stumps have taken me as long as six hours to remove such as one I had removed recently that belonged to a 96 foot tall pine. Had to dig a ramp by the time I got it broke loose just to drag it out of the hole and could only move it by grabbing one side and dragging it a few feet and then doing the same with the other. Hole ended up 6 foot deep and there were many large roots to deal with. Also like to see someone else using the blade to help carry a stump and have done a bit of that with oak stumps myself. So far about 400 hours on my machine with no issues. 24" bucket on mine and hydraulic thumb.
If you have instagram you can message me there, or I can give you my number there. My instagram name is “duckarolltape” And I’d enjoy helping in anyway I can.
