Yes, you can extend your 30 day Visa exemption by another 30 days.
I’ve personally done this on a German passport in January and my girlfriend did it on a US passport. Afaik immigration practices haven’t changed since. Please correct me if I’m wrong, since I intend to do the same extension next February.
It’s 1900 Baht and takes a couple of hours at your nearest immigration office. The one in Bangkok is unfortunately pretty far out in Nonthaburi.
One thing to keep in mind:
If you need to show an onward ticket because you’re flying in, they usually want to see a ticket in the next 30 days, not in 60 days, even if you explain that you want to extend.
If you need to get around that, I’ve summed up 7 methods to show an onward flight without having one on my German speaking travel blog.
I’d be surprised if Visa runs are a thing of the past. The same day border hop ones are out of the question by now, but if you leave for a week or 2 and get a 2 month Visa in a neighboring country it shouldn’t be a problem at all. No guarantees and you can’t do this back to back too often.
Also there’s the new triple entry 2 month visa now, the so-called “6 month tourist visa” but it’s a pain in the ass to get one.