Somehow among the multitude of threads about crankshaft position sensors on the forum, I missed the discussions about heat being the likely cause of failure. Nor did it occur to me to retry the cleaned-up old one until after I had installed the new one. Thanks for the info.

Aside: My car sat unused in the cold, damp, slightly below and slightly above freezing temperatures for two weeks before exhibiting bad behavior and throwing the P0335 code. The bad behavior vanished a few hours later when the car restarted and ran fine a few times, but by that point I was afraid of catastrophic part failure and was committed to replacing it.

Possible tech tip: While talking to an ex-Chrysler/Stellantis guy the day after doing the replacement, he said that it was easier to access the crankshaft position sensor from the under the car. Perhaps someone with a lift can confirm.