> They don’t just lean into epsilons, the session context tolerance is used for almost every single point classification operation in geometric kernels and many primitives carry their own accumulating error component for downstream math.

The GP wasn't wrong. To "lean in" means to fully commit to, go all in on, (or, equivalently, go all out on).

I think his point is: rather than "leaning into" it as in, masking through epsilons, he argues that tolerance is fundamental to the problem space, not a way to resolve edge cases.