> And most IPV4 addresses are vague and only give a coarse location of where you are

That's not true, you can request/compel Frontier to tell you what specific customer that IP was assigned to at a given time.

> and they're typically shared among many others so an IP is not a guaranteed signal that it was 'you' who pirated stuff.

Most residential ISPs in the states have 1 ipv4 (and possibly ipv6) assigned per customer and don't CGNAT, from my brief research Frontier doesn't seem to use CGNAT at least for residential internet.