Sparky FSPE 85 Pro
After some further testing with higher quality blades the problem seems to be the blade holder and the blade roller aren't correctly aligned, the result being the blade and base aren't at 90 degree angles. It's off, and I can see just be looking down the base at the blade from underneath. The roller has some play on each side, but when the blade is locked into the holder, it pushes the roller right over to one side, meaning all the play is on the other side. I assume then, this is why the cut starts out further right and gets pulled left.
I'll be returning it. Build quality overall for great, except for this issue of course. I'll look into a Makita instead