White dwarf seen to survive its own supernova explosion

So, is there anything about this type 1ax supernova that can be used to eliminate them from the data that uses type 1a supernovas as "standard candles" to measure the distances to galaxies for the purpose of estimating the Hubble Constant? Or, are they so similar in brightness to regular type 1a supernovas that it doesn't matter?

The part about the light output being powered by a different set of short-live radioisotope byproducts (Fe55 instead of Co56 and Co57) makes me wonder if the light output is really identical.

And, it also makes me wonder if the isotopic makeup of the stars in distant galaxies can be assumed to be the same as we have here in our own region of space. Larger distances mean earlier times, when fewer star generations had time to make "metals" (i.e., elements heavier than helium) in the gas and dust that collapse to form newer stars.

IF the isotopic composition of white dwarfs does change in a substantial amount as a function of distance from Earth, and that does affect brightness, wouldn't that skew the estimate of the Hubble Constant for the part of the curve that assumes all type 1a supernovas have the same intrinsic brightness?