Lanthanum glass is used quite often.. the radioactivity is so low that it is below natural background levels and thus not considered hazardous. I’d be willing to bet there is a lanthanum glasstype in more than 75% of modern high-performing visible optics. Thorium is very, very rarely used, and never used for consumer products.

From my perspective, a modern Petzval is trivial to design and resultant images would be impossible to distinguish from those of originals. Technically easy. The problem is not enough demand for a reasonable price tag. Get a million fellow photogs buying them and it’s a different story.