Norman, I doubt very much that Hugo is an overtightener, I think that particular threaded component is more susceptible to a reluctance to unscrew due to the taper fit and the joint sealant used, Hugo had used Red Hermatite as he had done so for years, I prefer a light smear of Wellseal on the taper and a few threads also, never had one jam yet and always use a K1 spanner as I do not suffer from the generous crankcase casting problem. The valve caps are a completely different method of sealing as you know, very little tightening torque required and normally very easy to undo.