Ah, thanks for the clarification. Yes, for me SITD on the longarm is a challenge. On a perfectly placed, perfectly stitched, perfectly ironed top, channel locks could work, but the truth is you have to keep making tiny adjustments. SITD is supposed to be on the low side of the seam and often it switches sides, blocks aren't exactly square etc. I go really slow and use a quilting ruler designed for long arm use. I needed a special ruler foot and extension table to use it safely. Don't know if you could use it with a domestic. This is one task that was easier on my domestic! The two suggestions I've heard are to stitch 1/4 on either side of the seam. It's less obvious if you waver. Another option is to do a wavy line that crosses back and forth over the seam.