Front trigger first, from day one on all my doubles, way to late in the game to be jacking with the system, V/C 577 had an articulating front trigger when I first got it, on firing that shoulder pounding beast and closing right hand grip even more to control torque staying in the gun and on the sights, I broke that front trigger.
Drove it up to JJ, he fixed it at no charge, well crap, I broke it again, this time he installed a solid trigger, GTG for more than a dozen years.
All that said and what I believe for most doubles being so decisive taking game animals the right barrel has more wear than the left barrel, it's the case with my little 303 British double, I often fire the left barrel only, with either 215 Woodleigh soft or CEB 210gr flat nosed solid, will even have an empty hull in the right barrel to give breech face a nice even area for the barrels to recoil back into.
Of course on hunts they have soft on right solid on left.