The answer I have been given on another forum….
Mladen Martin Radman Mark Hilliard, I am using 280mm f4 ROM but that is irrelevant, it works same with TC14 & TC20 and all R lenses compatible with either one or both of TC's with or without ROM chip, etc. As I suggested it is mechanical aperture lever coupling between R Camera, TC & R Lens that needs to be engaged in particular sequence but it can be tricked into engaging by moving aperture lever on TC first. People in the Leica shop especially if new to R system would be clueless as they already demonstrated, waste of time unless you wish to educate them. We discussed this on LUF (Leica User Forum) to some extent, follow link here
http://www.l-camera-forum.com/.../303566-removing-rom...
Removing ROM Contacts & Associated Circuit Board - Leica User Forum
www.l-camera-forum.comAd Hi, I've got two APO R lenses (100 Macro and 180 2.8) that I'd like to use on my new M (240) with my 2x-APO extender. However, the extender is non-R