I have plenty of self-raising flour (which will easily take me until its best before date to use) but am running very low on plain flour which I use predominantly for making a roux and then ultimately a bechamel. Given the current circumstances it seems appropriate to use up things I already have in the cupboard, rather than purchasing more if I don't need to.

Will the added raising agents in self-raising flour (the flour I have is from Sainsbury's and contains Calcium Phosphate and Sodium Hydrogen Carbonate, apparently) affect the production of a roux and then ultimately a bechamel sauce from the roux?