My point is that there is a documented listed of supported curves for ECDSA but attempting to use any other safe curve in the list results in a failure. I am not trying to use some arbitrary curve.
If your point is that no safe curve is permitted because the powers that be don't permit it, TLS is doomed.
https://eff-certbot.readthedocs.io/en/latest/using.html#using-ecdsa-keys
The default is a curve widely believed to be unsafe, p256, with no functioning safe alternative.
That's Bernstein's website if anyone was wondering, showing p256 is unsafe.