Alternator charging at consistent 14.7 V

The proper float voltage for a lead-acid battery is also temperature dependent. (Higher voltage in cold temps, so obviously, lower voltage in hot weather). It's not a huge change, but the nominal 13.8 volts is at 77F. Not only that, wet batteries vs. AGM have different requirements too.

Underhood (or in-trunk) temps vary a lot with ambient temp, sunshine on the hood/trunk, etc.
Charging at High and Low Temperatures

So 14.7 volts at the battery terminals is a little high unless that was measured at near-freezing temps, but won't immediately cause a problem. For an Optima battery it'd be closer to correct.

One more thing - is your voltmeter accurate? Could be several tenths off...