Absolutely agree, but convenience does not trump security, verifiability etc. In the example you gave, mail-in ballots were primarily introduced as an exception to the rule, in order to increase participation. They are not a wholesale replacement for ballot-box voting.

In Washington, Oregon, and Colorado, voting is entirely by mail.

Really? You Americans and your strange ways :-)

I can see then, why for some, the argument that "e-voting can enable use of standover tactics" falls on deaf ears - because the risk is no different than what is currently the case.

It's true. I can see the risk here, since I could easily pressure my wife into voting a certain way or even fill out her ballot and forge her signature (if I ignored the warnings that it's a felony to do so). I think we have to weigh that risk against the benefits of greater participation/accessibility that vote by mail provides.