I ran a Motorcraft (NOT Synthetic) FL-1A for 30,000 miles back in the early to middle 90's (3X oil changes, same filter) on a 400M V8 F250 doing a LOT of pulling/towing.... and it held up great.
It looked perfect when it was cut open. No sludge, no failures.
I don't think you have much to be concerned about running a synthetic oil filter to 50,000+ with regular oil changes and a very clean engine internally.