I have seen enough because he's is not a good blocker. Even Left tackles need to block. I've watch games a second sometimes third time and mainly focus on the Online. I've listed the troubles he still has. He doesn't hold blocks long, I'm guessing that's a strength issue, after 4 years of college and three of NFL strength and conditioning. He misses blocks too frequently. Like totally whiffs. He is a poor blocker in space, again completely missing his assignments. He takes bad angles and defenders run right past him. When he does lock on he ends up going backwards. I am not the only person here who sees this stuff.
So, what makes anyone think he can block better at OLT? Is it because he has another half a second reaction time? I just don't see it. A Olineman needs to be able to block well, or good enough. I wouldn't want Goff to rely on Joe's blocking his blind side. Evans is the current backup OLT as far as we know. From reports last year the coaches love him. So they try Joe at guard, since he's been displaced. He can move, but now they know he cannot consistently block.