Morning!
If monofilament thread is what you really want and you also want to FMQ a pattern in the blocks instead of in specific areas of each block, how about sewing temporary lines around each block and then put your monofilament thread in the bobbin? Then FMQ with the underside of the quilt up. Remove the temporary sewing lines around each block when you are done with the FMQ
Also, correct me if I am wrong, but I think I remember that there are different thicknesses of monofilament thread.
Another few things I just thought of: make sure the bobbin case, etc. are really clean; oil anywhere oil is indicated for your machine; and the last thing I can think of before you give up on the monofilament idea is a larger needle with a larger eye (remember that the eyes of needles sometimes will shred the top thread so try a few needles before you throw up your hands in disgust); and lastly, play with your tension and try sewing a little slower.
In another life that I miss terribly, I volunteered in the sewing rooms of a number of Drum and Bugle Corps and my sewing machine and I sometimes traveled with the corps. We did costuming, sets and sets of flags, alterations, and creating uniforms for the players (the exceedingly tall horn player from the UK was a fingernail biter of a project - entire uniform from scratch; no pattern but the right material) but he was so nice that we bit our nails with smiles on our faces. Bottom line: there were many different machines of various ages as well as many different volunteers with varying sewing skills and the mix of people and machines allowed us to learn from each other.
All the best, Pat