Reading all I can it appears to be a finicky rifle
I don't really like mine, but I wouldn't say it is finicky. My frame is an regular stainless Encore. I bought mine used and the trigger is nice and crisp with a reasonable weight. Not sure if there was work done before I bought it or not. I haven't had any trouble with it shooting any of the ammo I put into it. I had a 460 barrel that was not at all accurate, but that is a known issue with the twist rate on factory barrels. For everything else I was able to find a couple factory loads that shot well.
Best sources of info are TCencoreclassifieds forum and specialty pistols forum.
MGM and Mike BellM barrels are preferred by most of the people that are big into them. BellM buys blanks from MGM and does the crown and chamber work as I understand it. I was happy with service from BellM
Ed at Ed's contenders can usually get an MGM barrel for less than they sell on their site. I was really happy with my dealings with him.
All that said I have never been convinced it was cost effective in comparison to a regular rifle in each caliber unless the shooter wants to shoot odd ball cartridges that aren't commonly available in factory rifles at a finish similar to an encore. If you read on those sites you will see many who really like them have a dedicated frame for each barrel they shoot often and one they switch a lot for the calibers they don't shoot regularly. Pretty expensive at that point for a rifle that isn't too pretty.
I have had to call once for parts since TC was bought out. It seems they didn't keep many of the employees when they moved the machines and no one in the CS department knew anything about them. That has been a while, but it was frustrating. E Arthur, Ed's contenders, and Bellm will help you out though.