There is no such thing as “right to access algorithms” under the GDPR .
Section 15 first paragraph letter h) GDPR only gives the right to obtain
meaningful information about the logic involved, as well as the significance and the envisaged consequences of such processing for the data subject.
but this definition can hardly be considered as a synonym for algorithm, thus is just plain wrong to say that GDPR deals with mathematical methods.
As it should be well known even outside the circle of the Intellectual Property cognoscenti, within the EU algorithms have no legal protection (and this is rightly so, because you can neither copyright nor patent mathematics) so the only way an industry can take advantage of a specific mathematical method (i.e. an algorithm) is through secrecy.
Pushing the GDPR reach more far from what is written into the law means to force a company to withdraw from the only way to protect a company’s valuable assets.