That is certainly an advantage, but the matching one or, more often, two elements still vary and that has to be accounted for.
Its crystalline structure also means it can't be heated to high temperatures safely for traditional coatings.
I note that Canon, in discussing synthetic crystal calcium fluoride claims it takes four times as long to work. Now this was in some obvious marketing hype designed to promote their L series lenses - and perhaps justify their high cost - so I'm taking that with a grain of salt. But I have heard a number of claims that fluorite is more labor intensive and requires special techniques.
Again, in the end product, I don't think the choice of fluorite, FPL53, or the newer FPL55 should be considered a deal breaker. There are obviously fine examples of lenses using fluorite on the market, and others using FPL53. Since FPL53 is gong away, we'll be seeing FPL55 based designs before long.
Clear skies, Alan
CFF is already putting out FPL55. I appear to be in line for the fall, don't know whether it will be FPL 53 or FPL 55.
I will say that the Dragonfly array has caught me up short on this light scatter thing. I always thought it was nonsense. But these guys are using the principle of ultra low (fluorite technology) Canon lenses to find dim extended galaxies that scopes like Keck can't touch. GN