Update to this.
In May of 2021 I did a cross between two lidless plants – S. leucophylla ‘Bris’ x S. flava “lidless giant”. It’s a pretty interesting primary lidless cross. Seeds harvested in Sep of that year. Five seeds were harvested. Three germinated. Two survived. And I am sure glad those did.
I had them growing outdoors this year. They’ve developed slowly but steadily. One is now showing some characteristics worth noting. So far, it appears that one has that lidless flava influence. The “nub” doesn’t have pronounced undulations, like S. ‘Bris.’ It also looks like it’s keeping the interior dark coloration on the neck, while taking on white markings from the lidless leucophylla. The other pretty small, but showing some similar signs. Exciting stuff. These are still young plants but I’m fascinated by what I’m witnessing so far!