If you haven't checked back already, they fixed this. See upstream in the thread.

Glad to see they were responsive. I like their work, and love that they've been doing a great job of addressing my actual needs (adding recurring billing, fixing the button nigh instantly)

A co-branded button might be a feature in the future, but that effort was a swing and a miss.

Agreed. Hope they don't pull a twitter and require devs to use their buttons.

We definitely won't require the button. Hopefully we'll make it useful enough that a lot of people will want to use it. But we also recognize that everyone's needs are different and don't want to force a one size fits all approach onto all our users.

Weirdly enough, I think if you don't require it, I'm more likely to use it anyway. I call it the 'how dare you' syndrome.