Legacy option for key length?

[Peter Moody]

> I think a very good question which needs to be asked is, what value does
> disallowing shorter keys bring over severely deprecating them

like you said, they have only been severely deprecated. further, you
have been told exactly how to enable them, here
https://lists.mindrot.org/pipermail/openssh-unix-dev/2018-January/036535.html

you seem to want someone else to do all the work for you.

good luck with that.