Sealing the edges with glue size or shellac helps a bit but it's not really what's causing the tearout in birch ply like that. The real problem is the feed direction and blade choice, plywood has grain running both ways so you're always cutting against it somewhere. A zero clearance insert on your table saw and a fresh 80 tooth blade will do more for you than any sealer will. Also that $32 stuff is likely big box birch which has super thin face veneer, so even a tiny chip shows up huge, while real cabinet grade ply costs way more and has a thicker face. Tape your cut line with blue painter's tape and score the line with a knife before cutting, that trick saved a lot of doors for me. Sealing is more for paint edges and mdf, not stopping blowout on ply.

Been there with a 24 foot monster on a beach house last year. Got about halfway up and the ladder started sliding sideways in the sand and I had to just ride it down and hope for the best. That sinking feeling when you know you're going for a ride and there's nothing you can do about it is the worst. Took me a solid week before my hands stopped shaking on tall stuff. Bringing your own straps on every bid now is just smart, better to look like the careful guy than the guy who ate it off a wall.