Most machines come with a leveling tool. It is a plastic piece to use when going over bulky seams. That really works. Check what came with your machine.

this is a trick I learned for hemming jeans, same problem. When you get TO the thick spot, stop with needle down and raise the presser foot, behind the needle put some folded fabric or even paper that's about the same thickness as the seam, put the foot back down and sew through the seam. It's something about balancing the foot at those seams, there is a gadget called jean-a-ma-jig or seam-a-ma-jig that works great because it's made for it, I think I've seen them at Hancock's before.

I've never seen anything like that come with a machine, interesting.

I was thinking of a tool too, such as the hump jumper for maintaining stitch quality over seams, but I don't think those will work with FMQ because typically you want to avoid stops.