Sounds like you use an RPE based approach, Good stuff.. I wear a belt up to 225 usually. This is a 4x10mm belt so its not nearly as thick as a legit Inzer belt or something like that. Back when I did powerlifting I would never do sets like this usually, If I did it would be during a hypertrophy block and with more weight, 225x? Reps does not carry over to Max effort IMO when you are squatting in the 400s. But it def helps with cardio vascular endurance and hypertrophy!