NCCDB or USDA

NCCDB is user submitted data, and USDA is of course government data. I use USDA whenever possible

This is incorrect. CRDB is user submitted data. NCCDB contains lab analysed foods, just like USDA.

Here's a quote from the support article on this subject:

If your priority is to use the most detailed information for a food, we recommend choosing entries from the NCCDB (Nutrition Coordinating Center Food & Nutrient Database) or USDA SR28 (United States Department of Agriculture National Nutrient Database for Standard Reference) in the Common Foods Tab. These entries along with those found from the CNF (Canadian Nutrient File) and IFCDB (Irish Food Composition Database) have compiled results from lab analyses and research papers to provide us with a comprehensive nutrient profile.

That's from here: https://support.cronometer.com/hc/en-us/articles/360018239472-Data-Sources