I went "whole hog" and got a "
Pentagon locks chain-lock 110". It is...impressive. It is also
MASSIVE and
REALLY HEAVY! If I had a regular bicycle I'd be saying "nope, this is too damn much weight" and I'd never use it, but with the eBike I just wrap it around the rack and keep it with me. I also have a fairly hefty security cable that I thread through the chain-lock so that I can also secure the front tire.
In the garage (I'm in a very low crime area) I keep the garage door closed and use just the chain and trust the 75lbs of dead weight to help deter theft. I've considered also mounting an eyebolt but haven't done it yet and probably will never get around to it.