Hiii

They will get much, much bigger, you are only at the beginning of flowering..........buds generally take 8-10 weeks to fully ripen. Reduce your nitrogen input though, over feeding with nitrogen will encourage leaf growth instead of flower growth.

Bud size is mostly about genetics, but if you branch out a plant too much, you spread out the growth more too... "too many mouths to feed" idea. I'd wager this is more about genetics. You've got a lot of axillary growth, but it's not signfiicantly over-crowded that i can see. Just an autoflower with meh buds. Not too unusual. Stick to ~3 colas per sq ft. Keep them level in stature. You'll get more consistent buds throughout canopy. you want your primary colas originating off the trunk of the plant and not side branching of side branches. slightly overfed won't cause this, but you do want to dial back the fertilizer slightly. Start with N, as it's the most likely reason for the slightly dark leaves. Small problems require small adjustments.

Clawing on some of the leaves along with dark hunter green leaves leads me to believe there is some nitrogen toxicity going on. Too much nitrogen and can't take potassium correctly causing smaller buds. They don't look too bad though. Without a diary it's hard to give advise on how to improve. Depends on grow medium used, nutes you are using, watering habits, etc. Too many variables. Yes they will get bigger as you still have some bulking up to do as well. Best of luck and Happy Growing!