For my own hobby use, I tried bicabornate. I made some tries using artist gloss acrylic heavy gel instead of PVA glue, the result is nice (a bit "wet" perhaps) and for now it's not yellowing or changing. I don't how long yellowing usually appears.
The sample figure I based is staying under french south west sun all day, with no problem for now (I don't know if the yellowing is caused by UV or moisture?).
For my commercial scenery I bought Noch/woodland scenics snow flakes. I never used it before, we'll see.