Sage is still around? For a while, it was stagnant and then was sort of forked. There were some rendering/vulnerability issues that were not being addressed in a timely fashion (in some cases in one fork, in other cases perhaps in both forks).

Do you know enough about it to briefly describe where it is at, now, and/or which fork (if still forked) is better and why?

I haven't looked at it in... some years, now.