All that and no mention of IPv6? At least get the basics down first.
To be completely honest, I find ipv6 wildly alloying, but I guess that means I need to learn more!
Honestly I just use ipv4 and turn off ipv6 everywhere. Then I have just one configuration and one set of firewall rules (in and out).
In some magic happy land where you can use your IPv6 prefix over both WANs, then yeah, things can work, but that doesn't work for residences, generally.
The catch? _No IPv6 support whatsoever_
I wasn't even aware you could use HE's services without being a customer!
It's been around for a long time! If you do the IPv6 training certification, they do eventually send the t-shirt :P
EDIT: They also provide free DNS for up to 50 domains at dns.he.net which is also worth looking at if you don't want to run your own for every little thing.
I had to run a DNS proxy to filter out AAAA records for any Netflix domains.
For sites that use HE.net and have more than one IPv6 subnet, I use the initial /64 for the DMZ, so that didn't matter on most of them. Small sites had just been using the /64 though, and I had to renumber those. Total pain.
The norm seems to be for hosting services to contract with both HE and Cogent if they decide to go with one of them. This is why for typical client browsing you wouldn't notice--the other side has ensured you can reach them. HE seems to be the cheaper option, so people will route most of their traffic through HE, and then separately contract with Cogent for the smaller amount of traffic originating from/to Cogent networks. Alternatively, you contract with another network provider who handles that idiocy for you.