@graf@jonwzee Unfortunately, I cannot guarantee that I will never use a browser's user agent. Sometimes site admins don't respond, can't or won't change their rules discourse.bazqux.com/t/deviantart-issue/336/6?u=vshabanov and changing the user-agent at least temporarily (along with increased rate limiting) is the only way to get around the blocking.
It's not done often (and I actually removed the browser user-agents for the 3 remaining sites yesterday and they work fine), but it's a useful option to have.
BazQux doesn't make a lot of requests (precisely because it's not a "free" service with millions of users), so user-agent spoofing is used for badly configured sites with unresponsive admins, not to circumvent rate limits.
In the case of poast.org, it was laziness, which I admit is wrong.