I'd be pleasantly surprised if new PCEs (24, 35!) came, but don't hold your breath. There were leaks for years (and a redesign) before the 19 was released.
Note that they have field curvature (19, 24, 45 - haven't critically checked the 85), so not straightforward to get sharpness where you expect/want it. As Paul says, you definitely need to shade the 19 - it will flare from open sky or a window if inside. For filtering, Haida has a 150mm holder that bayonets onto the 19, with other inserts available.