Yes.
> Without a clear, business-first reason for an engineering project of that magnitude, it's not ever going to be a priority or a realistic option.
I'm not suggesting that there is any realistic solution. I'm simply stating that the cause of your pain isn't py2 to 3, but bad development practices that existed independent of language or migration. These were going to cause you pain at some point no matter what. It just happened that py3 was the forcing function, as opposed to something else next year.