I have had them both ways , on my old 78 I had the trailmaster side by side upper mount , stock lower , (dont know if they make that mount anymore) and I dont recall bending the lower mount with that set up.
On my 77 crew I have the factory dual shock mount (staggered) with the stock lower mount. I though I had my custom mounts on my crew but I do not , (I am getting old and losing my mind). My boy said I broke that front end in my 77 step side jumpiing it quite a few years back .
Anyway , I have had three trucks with the factory dual setup and have bent the lower on all three off roading. I will not be putting the custom lowers on my crew because the dauls are just for looks and it really never goes off road , did'nt build it for that.
Its really easy to make the lowers though , just get a piece of channel that fits the shock bushing width and cut it about 5 to 6 inches long , gig it up at the stock location and angle it right with the shocks mounted at the upper , then tack it. Then cut some 1/4" steel triangle's for each side of the channel , weld it all up , good to go forever.