Here's what the ignition system is on a Remington Ultimate, which short of a difference in hardness and threads, is identical to the Ultimate Firearms breech plug. For fact, Remington purchased the rights of the patented UF breech plug for their Remington Ultimate Muzzleloader.
The UF breech plug, even with miracle lubes, once fired a dozen or so times, is almost impossible to remove without breaking it, then you'll end up drilling it out and using a large EZ-out to remove the remainder.
UF/RUM breech plug
View attachment 5995
Permatex Nickle Anti-Seize is what was put on these threads, which is made to withstand extreme pressures and temps.
It wouldn't work either.
View attachment 5996