My only concern about doing it by district is that it will make federal gerrymandering THE supreme agenda, and rodents would attempt to pack as many Republicans into single districts as possible, so that they’d win huge majorities in a handful of places while the rodents carry more districts narrowly. Since White Republicans are not a protected political class and enjoy no rights as per the Justice Department is concerned, they could engage in mass disenfranchisement with impunity.
Obviously, having a Maine-type method of allocating EVs would increase the incentive to gerrymander districts, but it’s not as if such incentive isn’t present already. Personally, I would prefer that the congressional-district method is adopted by states that vote Democrat for president but have Republican state legislatures. : )