If my machine starts stuffing fabric down into the needle slot, that tells me my needle is getting dull. Otherwise, I rarely had that issue, especially since I tend to chain piece and use leaders & enders.
For me, key was to
make a note of the settings on the machine once I had my seam allowance dialed in so I don't have to figure it out again all over again each time I use the machine for piecing. On my 6600 I discovered I could change the default needle setting, so now when I turn my machine on it automatically moves the needle to the correct position to give me a good seam allowance with my quarter-inch foot. I have several machines that I switch between using; I usually have a post-it note floating around in the accessory tin with particulars on how to get the right seam allowance on that particular machine. The exception is my Rocketeer - if I put my quarter-inch foot on that machine, it has a precise scant quarter-inch seam without any adjustments at all. Like magic.
