You mention that you had the knee kicker backwards for two years, and I get that it solved your buckling issue, but holding it at 45 degrees is actually pretty common down here in South Florida. The angle helps with certain carpet pads and the way rooms are cut. I don't think you had it backwards. I think you just found what works for you on a tricky install. Tom might be used to a different pad density or a straighter wall layout, so his way isn't the only way. What matters is that the seams lay flat, and if straight on does that for you now, great, but don't trash the 45 degree angle completely. Some of the old timers near me swear by it for glued down carpet. You might have fixed one problem and traded it for another on a different job.

Keep it simple next time and let the clip do the heavy lifting, that saved me.

Man, that's the universal sign that your car hates you and wants you to suffer specifically lol. Glad the cheap parts tax finally caught up to someone else, not just me.