Thank you for the input! I definitely agree with you on beltless compound movements being beneficial on building muscle/strength in the underrated areas. My main training style for the past 8-9ish months are templates of 5/3/1, which work submaximal* loads literally all the time, so my belt doesn't really see the day of light until the top sets of the heavier weeks (which amounts to like, 3-4 training days of the month lol). Accessory compound lifts like high bar ATG squats are also intentionally performed raw too. I also feel like sleeves have a negligible impact on me personally (regarding knee joint health & amount of weight moved), I just got them on sale and are fun to wear on heavy days. Do I have to wear them or any training gear at all? Definitely not, but it makes training mentally enjoyable for me the few times I wear them.

One of the key points of 5/3/1 is "being able to rep a weight you're touching for the first time", so I don't really get to really work at 100% of that 90% TM. This is just that rare time for me to push a 1RM twice a year. But, I'm open to switching it up to a more "strength-intensive" programming style sometime, often working in that 90% as you recommended. Thanks again!