>
> Good question.. Since you don't really have the input(s), I think it's
> fine to always assume sufficient time/height on CLTV/CSV checks.
>

In this general signing-a-script context, I think a verifier might want to
see the time conditions under which it may be spent. The proof container
could include an optional nLockTime which defaults to 0 and nSequence which
defaults to 0xFFFF...


> I think it would just use the default (SIGHASH_ALL?) for simplicity.
> Is there a good reason to tweak it?
>

I took another look and there should definitely be a byte appended to the
end of the sig so that the encoding checks pass, but I think it might as
well be a 0x00 byte since it's not actually a sighash flag.