Hi Philip.
You do not say if you are a member of any of the many clubs/societies around the country, if you are not then I would strongly advise, as a first step forward, that you do consider joining one. By being a member you should be able to gain a lot of information on the current ‘new regs’ as you describe them, along with their implementation. There are several different ‘umbrella’ Associations/Federations around the UK but they should (?) all be working to the (in)famous ‘Blue Book’ which sets out all of the requirements for boiler testing, However you will still not beat talking to a ‘club boiler tester’ in a club near you to get the most up to date and best information.
Stan B