…or you could make a balance board.
Also you could practice standing/squating on an under inflated squishy rubber ball like this. If you want to focus more on balance than strength raise the air pressure. Any athletic ball would work but a squishy one like that would improve strength more.
A great leg strengthening exercise that can be done anywhere is pistol squats. To reduce potential stress on your knee, keep your leg and upper body as far forward as possible (eg. leg streight and hold onto toes). If that’s too easy close one or even both eyes, or do it on any of the contraptions previously mentioned.
Getting good at doing any of these on one foot aught to improve awkward pedal grabs, as well as a bunch of other stuff.