Trail Boss is smokeless nitro based powder. Smokeless powder does not work in Ruger Old Armys or any other percussion style gun. It has nothing to do with the strength of the steel, I am certain the ROA could withstand modern cartridge revolver pressure.
It's the ignition system that is not suited to smokeless powder. Black powder only needs to be set on fire, a single spark from a flint on steel will suffice. Setting black powder on fire is all that percussion ignition was designed to do.
Smokeless powder needs a sealed primer. The primer's job is two fold. It must ignite the powder and it also establishes the initial pressure in the cartridge that smokeless powder needs to get into its fast burn mode. Simply setting it on fire results in squibs and bloopers and I suspect that the light load blowups sometimes reported are loads that began as squibs and then built up enough pressure to detonate the powder that was left.
I come to this conclusion based on my own smokeless experiments with an ROA, known safe loads for a Colt .45 in a ROA resulted in failures to fire or bloopers unless I put a small charge of black powder in the chamber first to do the job of the primer in a modern cartridge. I'm not giving out what load I used, if you want to do this, you're on your own.
If you wanted to use smokeless in a cap and ball, you would need a special cylinder designed to use sealed 209 shotgun primers instead of percussion caps. Such cylinders are actually available in some European countries where cartridge revolvers are highly restricted and people want to just shoot pistols.