Yeah, my inclination would be to say don't do that, too ...

That said, generally if I have a muscle that wants to cramp during an exercise, I can avoid it by engaging the opposing muscle. So, when you're putting your ankle in that extreme dorsiflexion, try tensing up the tibialis anterior as well.

Now, when I try that in my chair here, it makes my foot want to cramp ... so that's all FWIW.