The Battery Tender or one of those does have a profile that relates time in Absorption to the time it spent in Bulk. ISTR A time is twice whatever B time came to.
Absorption can go on forever, so some kind of cut-off is needed so it will start Float. Many chargers use about 97% SOC as their cut-off point to drop to Float (such as the PD converters) and the typical "automatic" charger will shut itself off there too.
That is where all this " 2% acceptance rate means full" comes from that I hate so much, when to me, "full" means 100% not 97%. :(