Is it possible to detect `grotty -i` at runtime?

[John Gardner]

I'm looking for a way to harden my .UL
<https://github.com/Alhadis/Mono/blob/25765171fbf676b623a4bcbf3d9f93384ef83040/ono.tmac#L171-L233>
(underline) macro against grotty(1) v1.23's new -i switch, which causes
italicised text to be rendered with actual italics (in TTYs that support SGR
3, at least). My intended workaround involves something like

\l'\w,\$1,u\(ul'\h'-\w,\$1,u'\$1

or some similarly atrocious hack. Unfortunately, there doesn't appear to be
any predefined register to report the status of grotty(1)'s -i and -r
switches (both of which change how italic fonts are rendered in the
terminal).

Can anybody confirm that what I'm seeking to do is even possible?

— John