In the UK all radios installed in an aircraft whether it is on a C of A or Permit to fly must be of an approved type and be licenced by Ofcom. Although the installation and maintenance in the UK is overseen by the LAA for permit aircraft, the overall standards are no less. The procedures other than the UK may be different in detail but not, I'm certain, of a lower standard.
LAA document: AIRCRAFT AVIONICS INSTALLATIONS TL 3.03 Issue 17 October 2019
Last edited by Fl1ingfrog; 26th Jul 2020 at 00:42.