My son is a big guy! He's 4 and 43" tall and 56 pounds. His weight, however is mostly in his thighs and groin. We've tried multiple 5 point harness seats but they all seem to squish his inner thighs and groin area to the point of tears. I am looking for a seat that might have the ability to have more room in that area before having to switch from the 5 point harness to just a high back booster. Id really like him to stay 5 point. I've currently tried Graco Extend2Fit, Chicco My Fit Harness+ Booster, and Graco SlimFit 3 in 1. They all seem to tighten so much more in that area. If there was any seats that had the buckle out a little farther, would be perfect! Any suggestions would be wonderful! Thank you!