Props to you, I'd be terrified of wall mounting that much weight, but sounds like you thought it all through.

I still fear that my wall mounted TV is going to fall down.

That is a strong wall

If you got some poor quality lag bolts, you'll need to find somewhere else to post the very interesting aftermath.

apart from driving massive lag bolts into 3.5mm pilot holes

Assuming this is USA/North American construction with 2x4 wood studs spaced at 16-inches (40 cm), I'm of the opinion that lag screws wider than 5/16 inch are a less optimal choice than Spax Powerlags, which are only 1/4 inch wide but get their strength from deeper penetration into the stud, as well as a higher pull-out rating (hehe "pull out game").

They're also easier to install because of the smaller (or as they advertise, entirely avoided) pilot hole, and that also makes it easier to not miss the stud entirely, since a stud only presents its shorter side when facing the wall. It even comes with its own washer built into the head (for the wood-to-wood version only). My at-home standard for weight bearing use is the 3.5-inch deep Spax Powerlag, because with a 1/2-inch wall fixture and 1/2-inch or 3/4 drywall layer, that still leaves around 2 inches of penetration into the stud.

BTW, for anyone in future, using too small of a pilot hole with too large of a lag screw (of any type) will cause the stud to split. This irreparably weakens the stud while also diminishing the strength of the screw attachment. So the likelihood of attachment failure is unnecessarily high. Yes, you're supposed to drill a hole slightly smaller than the screw diameter, but not overly so.

The right most bolt didn't quite line up with the stud, but it's secure enough for now until I remove the top piece and throw in a large drywall toggle bolt.

You can use 2x4 or 2x6 (depending on how you want it to look) and span it between two studs. Then you can bolt your pieces to the 2x4/6 more securely.

A more extreme idea would be to go get a sheet of osb sheathing and put it up on the wall. Then you can put things anywhere you want.

Nice 👍

My wife and I are finishing up our garage gym build. We have everything but the power rack. It’s supposed to ship next week.

That's real nice! Where did you get the rack from?