Magazines are classified based on what they were originally intended to be used in. They are advertised (intended) by the manufacturer as fitting a charger pistol. If Ruger or butler creek made a 25 round magazine that was “intended” for an 10/22 only and advertised it as 10/22, not charger that would be legal in Canada. Unfortunately Canada is too small of a market for most us companies to care or bother.
It’s similar to the lar 223 pistol mag deal. They are intended for a pistol so they can hold 10 but you can use them in something they weren’t intended for (rifle). If you modify a magazine to fit a different gun it’s still required to meet the regulations for what it was originally.
Dlask made the tuf22 magazines to only fit their 10/22 receivers and they never made a 10/22 that was considered a pistol. You could even modify a Ruger charger pistol to take tuf22 magazines and it would be legal because they are rifle magazines, as intended by the manufacturer
If Ruger made a slightly different 25 round magazine and stamped it “Ruger American Rimfire” and didn’t say anything about the charger it would be legal in Canada because that is a bolt action rifle, regardless of the fact that they would be interchangeable with a 10/22. They make a bx-15 magazine for their 22wmr and 17hmr bolt actions that is legal because it’s not intended to be used in a pistol and if they ever made a 10/22 in one of those calibers you could use those 15 round mags legally, until they made a pistol version of the rifle and advertised the magazine as compatible anyways