I'll copy in a text I sent to someone on him.
Watched Joel Ervin:
His frame was built in a lab. If you were creating a prototype, it'd look a lot like this guy.
Something I look for is how an OL can get into a stance. Ervin can actually hinge and slide those hips back. Huge for a guy that tall and long to be able to do. Often times they're just kind of doing half squats because they can't bend. It's a large indicator for their flexibility and ability to drop their weight (as an anchor, not dieting).
When he gets into space I love how he slows down and chops his feet. That's high level stuff. So many OL get to running and lunge top first at second level guys who easily avoid them. Like dipping your head and lunging. He's under control and patient.
Grip strength is already strong. He's driving and pushing when he's attached until the whistle. This is where the giant hands come into play. Power and grip strength aren't exactly the same, but you can see he clearly has grip strength already.
If you asked me my favorite rep, it might actually be a cutback run by the RB where he didn't block anyone. He gets out into second level and is sprinting with the RB down the sideline. It isn't just that he's pretty fast in a straight line. It's the effort and on-field character that shows. He never blocked an soul and could've stopped 20 yards sooner, but he was all effort and helped his RB up out of bounds at the end. I can win with a guy who cares that much and is engaged. In a world where the margins between "flame out" and true contributor are tiny, give me all the positive markers like this I can get.
Right now he could develop:
When he gets to contact he pops upright. He's bigger and stronger now, but that won't be the case here. Hinge and pop on contact and he will improve.
He loves to bury dudes. How hands get wide and he likes to throw guys down. That will get calls at college level. His elbows flare and are susceptible to be knocked down and then he grabs. If he forces those elbows in and hinges his hips more, this is a dude.
His feet are not especially twitchy. I think he moves well, but quick twitch off-the-snap is average. It's one reason I see him as a tackle more than guard as of today (I'm watching highlights, so there are giant error bars here for what I'd conclude watching several games with true pass sets etc.).
If you told me "watch his highlights" and put this kid up with Cantwell or some of the top guys, I can't say I wouldn't say give me that guy. His tools and on-field character markers are that strong. Obviously, it's not just about highlights, and current development, tools, character, now performance vs. length of runway to finished product all play large parts in an overall evaluation.
There is so much development and more to an OL than just height and length, but I saw a lot of markers for this kid to have a chance to be great.
He's got development runway to go, but the range of outcomes for him is first round pick.
Not sure why he's a 3-star, but he's better than every 3-star OL we've brought in in years (just saying to my eyes).