I wish I had data from when my AGM was new.
While I do not have enough plug in charger amperage to achieve instant absorption voltage, it would be a valuable figure to compare to now.
Tools and interest are required to figure out a battery's personality. Comparing new personality to aged personality, well I find it interesting, and collect data and try to figure out why this or that is occurring.
With an AGM, since the hydrometer is not an option the voltmeter and ammeter are required. Having a high amp adjustable voltage power supply is another valuable tool, for figuring out the battery, but the desire needs to be there.
with an auotmatic charger there one is then required to not only figure out the battery, but why the charging source does what it does in its goal to flash the green light and soothe the human who pressed its buttons.
Without the voltmeter, ammeter and the ability to achieve and hold absorption voltage, then the battery will remain partially or wholly, a mystery.
But it could be 'Just fine'. If 'just fine' is said slow and smooth enough, and repeated often enough, the human soul is soothed enough where reality is completely inconsequential, at that moment.
Only later can the petulant foot stomping and finger pointing indignation begin.
In general, Finger pointing, foot stomping indignation is apparently much more rewarding than the satisfaction of never having the opportunity to do so.