Anya - sorry you're finding Quitzin still giving you singles
The first year here, along with many other cultivars, it lost its buds to heavy frosts; the second year it was semi-double and this year was spectacular but I might still call it a semi-double
but you know - I think I prefer that to the full double shown in the registration.
The hairiness you first noted in Pastelegance seems very similar to that of Avant Garde but it doesn't stay very hairy very long in the Spring so perhaps if you look earlier next year it will be hairy again
I don't see it as an occasional 'feature'