Birdhunter:
Maybe you should try to examine an actual Greener treble wedge-fast action that has not been abused or poorly tightened. I can't speak for the 'continental' variants but you can rest assured that British makers such as Greener and Webley & Scott fitted them up properly at the date of construction.

The cross-bolt may have been a 'gimmick' in the sense that it was designed as much for capturing market share as improving the design of a double gun, but if fitted by a respected Brit maker they were always fitted properly.

Enlightened DR owners would never interpret the intervening century's wear and tear, coupled with ignorant or shoddy gunsmithing, as indicative of a well-built firearm's original design specifications.

Similarly, the current attituide of mass-production in a climate of fiscal constraint is hardly comparable to the skill and pride of workmanship characteristic of the heyday of British and European gunmaking a century ago.