Brown leather belt to match the boots I think would be an improvement. Tucking in a sweater does look a lil weird but not impossibly so. Having the boots, belt, and watch band matching is usually a pretty consistently good looking combo.

the leather jacket is cool but I feel like the buckles and zippers are a bit much, it can probably be executed better without the sweater. It’s like if Ned Flanders put on a bikers jacket lol. For that jacket I feel either black or grey jeans or weathered light blue jeans would do better, whichever aligns to your personality the most, and maybe black boots to match the jacket leather. That, or a lighter shirt/sweater would make the jacket pop more.

This is all very subjective and nitpicky advice and opinions. Overall the fit looks great. Gives cool uncle who biked to thanksgiving dinner energy.

Untucked preferred. Makes me uncomfortable just looking at someone tucking in a sweater.

Methinks too bashful on the green. In photos looks almost like faded black. Would either commit to black - black or a greener green.