We used to call coaster brakes "torpedo" when I was a kid and, yup, they're totally horrible.

If you've got coaster brakes I don't even know if you can learn to trackstand (you need to both slightly pedal forward and brake, and adjust by slightly pedaling backward): trackstand looks like you're idle but micro-adjustments are constantly happening.

Then I take it probably could wheelie a bicycle with coaster brakes but I fear it'd be hard: same things, you do micro-adjustements and they're not only done with the rear brake. I'm pretty sure I do pedal backward a bit when I do wheelies.

And when I readjust the position of my feet on a bicycle: I do it while backpedalling.

Last time I used a bike with coaster brakes I realized how dependent I became on being able to pedal backwards.