Can't extend curves on surface

Anyone know why I can’t extend the red curves (just dupe edges of the hole) along the surface? I also tried with ExtendCrv on the edges directly, same problem. Is this not working because of the curves being concurrent with the hole edge?

Thanks, --Mitch

NoExtend.3dm (46.6 KB)

Yeah, I guess that will turn out to be the reason, but it ought to work… Buggifying, thanks.