Julian
Radio navigation is required in training but it is not necessarily examined skills test. It is possible to test in an aircraft with no functioning navigation aids!
How can you see France from the UK? You clearly haven't been to the Channel Islands from the Bembridge VFR - at 3000 feet to remain clear of the airway. Or to Deauville from Shoreham. Or to Cherbourg in the VFR recommended route through the danger area. Or been refused clearance through said route, so had to navigate around it. Or to Brest from Plymouth.
I think it is you that failed to make any relevant point trying to invert my question. No-one has said that it is written anywhere other than local flying orders that a x-channel check is required. That is not the point at issue. Nor does it mean it is not a sensible requirement, which is the point at issue. It also doesn't mean that a qualified pilot shouldn't learn something useful from the trip.
I personally would have signed you off x-channel if you had checked out with another club, with one or two exceptions. On the other hand one of the clubs I worked at wouldn't let me fly x-channel without a checkout, even though I was checking out members of another club. When I'd done about 5 they then allowed me.
nuclear
They don't check very carefully. Technically you have logged it incorrectly, but even if they noticed they would only tell you to correct the small error, you wouldn't get into trouble. However major "errors" have got pilots into trouble, so I would always recommend you fill out the logbook carefully and correctly in future.