Plenty of both chert and flint in southern Ontario. I don't believe stone can be annealed, or why it would have to be to spark off steel?
Watch a bunch of flintknapping videos, and do some reading, and you will soon learn that heat treating knapable stone is (and has been for likely millions of years!) a thing that is done. Some guys simply chuck the rock in the fire when it's going good, and get them back when the fire has burned out, others have played around with different gas and electric ovens. It can, in some stones, make the entire difference between being workable, and not, while in other stones, it does not change the workability of it.
It is, to be pedantic, not exactly an annealing process as is used in metal terms, but it IS a heat treatment. Glass blowers do a similar process with their products, as it allows them to be handled and used without immediately shattering at the first minor impact, from the stresses trapped in the material on initial cooldown. Also, in glassware, they purposely induce stresses in safety glass (car windows, etc.) so it DOES break into gravel, rather than great bloody flying shards, when it is broken...
Based on what I have seen, it would do a fella some good to do some research into blade and core technology, there are a few videos out there, they will give you some idea how to preform the core so that successive linear blades of the correct shape can be got from the core, ready to be broken off as individual flints.