I actually initially wrote "a backdoor pilot for a completely different show" instead of "...for a spinoff". And yeah, it really was that completely disjointed from the rest of the season.
If they were absolutely dead-set on the basic idea of that episode I think it would have been better to do something like release it a month or two ahead of (or hell, even after) the rest of the season as a sort of "BSG: Razor" and then just write the actual season in a way that makes it clear that the standalone Eleven episode takes place in between the episodes 6 and 8 that we actually got last year. It would actually have maybe been more interesting to do it after since the feeling of wanting to find out where the fuck Eleven had been might have helped to get people to ignore how different it was...but either way, making it so completely different would have worked better if it'd been more explicitly positioned as quasia-standalone.