Daryl-

I too am looking forward to curing my chrono of it's headache and getting good readings on how this regulation load runs.

Funny with the fouling.
Swiss might have special magic around regulation loads for black powder express double rifles, but I'm not seeing it as having any particular edge between shots (in the fouling department)
I'm just not yet finding a good reason to run the expensive powder (in this rifle) or to deal with working a lube/wad combination to make it work.
Goex fouling with the previous wad column is soft and easy to deal with.
If I recall properly, this was also the case with the gamekeeper's rifle I sold last year, also with my Mahillon.

The Goex burns consistently too.
I've gotten great accuracy with it out of my flint rifle and my .54 caplock. Both of them foul soft and moist with the Goex powder (given the load has enough proper lube to do the job). Cleans easily at camp - but with the right lube I don't need to bother and can shoot day after day with no rust/corrosion issues if I keep the bores moist with fouling - even with my little carbon steel barreled .36 squirrel rifle.
I've gone days between cleaning my black powder rifles, shooting every day with no rust or pitting at all.
There's a little bit of load development focused on how much lube to include in the wad column, and it's worth it to me by way of consistent accuracy and ease of service, especially when we're talking about loading and running hunting cartridges.

Cheers
Tinker