Router is working, mostly. I don't know what the difference between L2PT and IPsec is, never heard of either until a week ago. Unless it was part of the out-of-the-box configuration, I doubt whether I'm using L2PT or IPsec. Sure not using them on purpose. Don't know how to begin using L2PT or IPsec. Or how to engage one or both. Or how they are related. Think of me as a virtual 10-year-old. I appreciate your posts but they are over my head. Please dumb them down for me.
Ok, let's start from the beginning:
"hEX is up and running. Sheesh, what a tough slog for a non-IT guy like me. Even now, I don't see how to get the router to engage warp drive and use hardware acceleration on my IKEv2/IPsec connection with 500 Mbps service."
So, You do have an IPsec connection working. At least, had for a while.
Now, re reading Your posts, I'm thinking You are the client on this connection. Right? You pay some VPN service, and connect to it. Am I right?
About not knowing what IPsec and L2TP are:
IPsec encrypts the traffic. It doesn't care about what the traffic is. But it is quite hard to setup right - with lots of gotchas and caveats.
L2TP is a tunnel protocol. It exists to create a virtual way between two endpoints. You can think about it like an virtual ethernet cable. But its cryptography is weak and outdated.
IPsec can be used with various different configurations:
One of them is pure IPsec - when You use just IPsec to create the "path" between the two endpoints.
Another is what we call L2tP/IPsec - we just create an L2TP tunnel between two endpoints, and encrypt it with IPsec. The biggest advantage is to avoid the really complex task of setting access and routing through IPsec. We only need to configure IPsec to the 2 L2TP endpoints. The rest goes trough the L2TP tunnel, and our lives are much easier.
So, to recap: are You a client? Is Your IPsec connection working? Even slowly, is it working?