If your exht valves were in spec and there were no shims, it is time for a revalve. Take the head off and/or the bike to a head mechanic.

I've adjusted plenty of valves (cars and bikes), but never before the bucket and shim style. It was difficult to get in there and I never felt as if I was getting a clear reading. What's strange is unlike all else on this thread, mine seemed too loose. I fit the largest feeler in and was even able to go up a few more mm as well. My 2014 KLX250 has 7,000 miles.

Any explanation or advice is appreciated.

Did you remove the valve buckets by chance and the shims are on your workshop floor?
Measuring that excessive amount of clearance makes one wonder

sheesh, I was 180° off. All is well.

This makes no sense to me... Clearance is taken when there is maximum clearance. 180 off should be actually on the shim I would think

the lobes were pointing inward, not outward as needed.