i like to use the toggle buttons for crouching and going prone, rather than just holding them, but i have noticed that i can stand, crouch, then go prone, but i cannot prone, crouch, stand. i have to press the prone button again to crouch, and then press the crouch button to stand. nothing game breaking, but can severely hinder the speed at which i change positions.

It's no problem for me, and I don't think it's really that big of a deal. I play fine with it, and I dont usually go prone, only on roofs

Good suggestion OP. I have the same problem.

The animation from going prone to stand takes a while, in the meanwhile you can press the duck button so that your soldier will go from prone to crouch without having to stand first.

I think an issue like this was mentioned before too. I'm personally not used to those toggle buttons, so the logic might be indeed a bit off.

I think I have a better clue now what is supposed to happen with the buttons.