I ordered a few spares, I'm hoping one but not all of them is domey. Something less o/s than the flats and less sensitive than the SFD's.
I sent Discmania a msg about these discs, having been so immediately impressed with them, and got a response which says, in part,
We do love the flat and stiff C-FD's too. We have already advised the manufacturer* to stick to the plastic blend used in those ones in the future runs too, but as the production is not fully in our hands, we can not be 100% sure that the disc will stay exactly the same.
The asterisk is to a note that they're mfg'd by Innova, etc etc. But I'm trying to set aside a few too, just in case.