I am fine with this, but in the longer term I'd rather have only one way of doing it. I agree this is not a huge problem though.

Sometimes the browser script doesn't behave for me

If you have steps to reproduce, maybe it is worth investigating. What I found is that sometimes the button either does not appear or clicking on it does not do anything. My experience is that refreshing the PR page always fixes it.

and this is easier to advise users to use...

There are some manual steps detailed in the doc for accessing the doc. I guess this could be improved (e.g. with screenshots)

As far as I'm concerned, the manual steps described in the dev docs are very clear. I will try the browser script.

Not sure why it was not merged before but I merged this. The scikit-learn.org/circle?<circleci-build-number> should be less broken that before.

Personally I would be in favour of getting rid of scikit-learn.org/circle?<circleci-build-number> in the long term but for now since this is in the doc so we may as well try to keep it working as much as we can.