You've got the wrong Palafin in those calcs, the one that you will be facing after a single switch out would be "Palafin-Hero", and these are the actual calcs:
0- SpA Palafin-Hero Grass Knot (120 BP) vs. 252 HP / 4 SpD Dondozo: 230-272 (45.6 - 53.9%) -- 46.9% chance to 2HKO
(Notice how I didn't even bother with a neutral SpA nature in there)
0 SpA Tera Normal Palafin-Hero Boomburst vs. 248 HP / 16 SpD Amoonguss: 186-220 (43.1 - 51%) -- 5.1% chance to 2HKO
So... Yeah lol
You're right, I did have the wrong form, so the techs are an effective lure.
They're still bad sets due to severely compromising the match-up into everything else, though.