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"Because of Stellarium’s fairly consistent inconsistencies, I use Frank’s data whenever possible."

In my experience, Stellarium's data for Sun and Moon positions is consistent and does not differ materially from data in my apps, at least in my recent tests.

Of course, you have to make sure you have a relatively recent version of Stellarium (your screen captures, Jim, are tagged as version 23.4, so that should be plenty new enough, but bear in mind that the current version is 24.1 --version numbers are now year-based). The biggest issue when comparing Stellarium data with other resources is making sure you have the same settings applied in Stellarium on each trial. And because of Stellarium's history, the relevant setting are scattered about in places that can be hard to remember. For example, there are times when we want geocentric coordinates. You have to enter the "Configuration" dialog, go to the "Tools" tab, and then uncheck "Topocentric coordinates". Unfortunately, there is no visual cue that coordinates are then geocentric. It's best to place the Moon in view near the horizon and watch it jump by a degree or so (topocentric "parallax in altitude") when you select or de-select this. I keep notes for an audit trail when working with Stellarium.

And don't forget that you may be using one of my web apps in a fashion for which it was not intended or with settings that are inconsistent on other grounds. Don't trust anything unless you have at least two sources that agree reasonably well. Or as Ronald Reagan was fond of saying, доверяй, но проверяй (*). :)

Frank Reed