Some non-PRM modified 150 toilets have floor based buttons you have to stand on to make the toilet flush or make water come out of the tap - I'm not sure that's allowed even in the second toilet.
Porter brook 150s have controlled emission tanks fitted with the new toilet , the angel ones don’t yet but it’s getting fitted
This kind of kitchen tap design is suitable for most, including those with arthritis:
https://www.plumbworld.co.uk/images/silksteel-product-25430-gallery-TmAf-default-H.png Although, for a train toilet you wouldn't want such a big loop on the section the water comes through.
I had the same issue in a public toilet the other day. Something had splashed on my coat and I just wanted a bit of water to wash it off but the handwash machine doesn't allow you access to the water before it's given you some soap.