I’m far from an expert on this, but my understanding is that that could work, but it could also fall foul of other building regs, specifically the H&S regulations of 1992, which talk about toilets being suitable and sufficient

In my inexpert opinion it’d be enough of a grey area that you could challenge it in court if you were told it wasn’t allowed. In practical terms, no company is likely to do this unless they were specifically trying to take it to court to challenge the law or bring it more public agenda

But it’s s good idea and I’d support any company that tried it