You said you can't see it unless you shine a light at the exact angle, and that's been my experience too. I did a similar 45 on a corner seam last spring and after I hit it with the polishing pads, my own customer couldn't find it even when I pointed right at it. The trick for me was to make sure the glue was fully cured before I even touched the sanding, rushing that part always leaves a faint line. People get way too scared of seams, but if you take your time and match the grain direction, it's a solid fix. I'd rather do a clean seam than tell a homeowner they need to drop another four bills on a whole new slab.

Double what Aldi costs" says it all. Total rip-off.

Ain't it funny how a hand tool just feels the threads better? I ditched my impact for terminals too.