Having had a brief look at the UK home video edit of HUMAN CENTIPEDE 2 [FULL SEQUENCE], I can confirm that - though still heavily cut by the BBFC for its "18" Certificate - there's at least two sequences present on the British version not available on the North American "On Demand" cut. Don't go reaching for your Mastercards so fast, boys - while it includes some footgae not available locally, that comes at the cost of over 30 cuts when compared to the US version, and there are actually jump cuts in BOTH of the "extended" UK scenes, so it's not as if cobbling the two versions together would recreate the uncut version anyway.
Without anything more solid at hand, here's the runtimes of the two versions floating around, minus warnings and dead space at the end of the credits of the former:
ON-DEMAND VERSION: 1:27:33
UK BLU-RAY VERSION: 1:27:51
The BBFC website says that the original, rejected version ran 1:26:50 - but that was on video, which in the UK implies a PAL runtime that's about 4% shorter than its theatrical incarnation would be. All we know for sure anymore is that the UK DVD is two and a half minutes shorter than its submitted length - roughly 2:37 shorter on Blu-ray. With that in mind we can assume that the complete, uncensored, 24fps runtime for the film is between 90 and 91 minutes - don't forget that runtimes are fickle bastards if studio logos or dead space at the end of the credits are included, so it's difficult to say anything conclusively without having an uncut version on hand to compare everything with... all I know for sure at this point is that the UK version restores two sequences not present on the On-Demand version, while the On-Demand version has numerous sequences cut from the UK version.
To make matters even more frustrating, there appears to be an alternate take to smooth over the big scene missing from the On-Demand cut! Without too many blatant spoilers (for now), I'll say that this shot is exclusive to the US release, and that the version submitted to the BBFC plays out VERY differently:
This shot is less than 3 seconds long, but it does leave me curious if the On-Demand version has any other footage not included in the UK Blu-ray that aren't directly related to all of those BBFC jump-cuts? Maybe if the Australian Classification Board bows to pressure and bans this after having cleared it once before (just like they did for A SERBIAN FILM), I'll be stuck being the asshole to provide a side-by-side edit report.