Bidet spray gun regulations

[Astrolabe]

I'm looking to install a bidet spray gun by the toilet, ideally this would involve sending hot and cold water into a thermostatic mixer then that would feed into the spray gun which would hang next to the cistern.
What I'm worried about is whether the spray gun would have to follow the same regulations as a full bidet system, i.e. the IRN R070 regulations discussed here:

Water Regulations Approval Scheme Ltd IRN R070

IRN R070 The Water Supply (Water Fittings) Regulations 1999, the Water Supply (Water Fittings) Regulations (Northern Ireland) 2009, and the Water Supply (Water Fittings)

www.wrasapprovals.co.uk

They illustrate a few solutions, but they all look extremely expensive and impractical in the space we have, and it all seems excessive just to install a spray gun? Does anyone have any suggestions or experience? I'm interested in any actual risk of water contamination but also in any legal risk if I later decided to move and rent out the flat for example.

 

[Elkato531]

The regulations are what they are for good reason. You cannot have a supply feeding a category 5 appliance without having the appropriate back flow prevention. That will either be an adequate air gap or a separate supply isolated from the rest of the system.