Will,
Just because in person, as both you and Mustang geezer know, I'm a chatty kathy, I'm a little more shy on the internet.
What does the top of your new piston look like that gave the better burn pattern?
As you know, the 200 uses the same cam and I run the same 250 oil pump with the high volume 427 georotor with absolutely no issues. Just lock tight on the cam sprocket and rev it a lot higher.
Ak Miller always said the 250 had a chain whipping problem and that the 5/8" chain worked better than the 1".
Did the powdered metal crank gear tooth break off and then jam or break the chain?
This may sound crazy but maybe you need run a larger volume oil pump to dampen the harmonics of whipping back and forth. Is your oil pump drive shaft in good condition?
I believe your crank damper is liquid filled. Maybe it just doesn't work for what you're doing. Maybe some SFI rubber ones that could be modified to fit, would work better.
Some of the 250s timing chain covers have a rubbing block, maybe a custom made nylon shoe would prevent some of the chain whip.
I don't think stronger parts will help. You have to stop the harmonics of the crank and cam from whipping themselves to death.
That's why I think a gear drive and tightly tie the two together would work better or a belt drive that would absorb some of the harmonics. Didn't Ford performance at a one time offer a wet belt for the 302 that could be adapted?
FTF engine is similar in nature as far harmonics go. What's he using?
How's that for chatty?