OP here. First, thanks for the replies.
I should have mentioned that my wife and I seldom travel to or from Thailand together. I usually arrrive in October or November and she generally arrives early December (some years she stays longer than 60 days)..
When she was preparing to go to Thailand in 2022 we looked at getting a Non-O on the website. It didn't require Covid cover, but did require health insurance (which we have, but not able to get an acceptable statement as it is paid monthly and not pre-paid). I just looked at the visa website in US and it is down now, so can't check for changes.
As she never stays beyond 90 days a Non-O would be fine if she could obtain it easily from the website. We wouldn't care about the dependent option.
As to border runs, I don't see the point. I already have the extension.