Years of experience with those very batteries
The SG is on those is low and ends up at 1.250 after an equalize charge, and usually 1.220 - 1.230 (depending on temperature) after a normal charge. They are actually designed to be charged by common marine chargers that don't have an absorb stage. Most marine chargers are constant current, and voltage gradually rises to 15.0 for flooded lead-acid then cuts back to float. The charge process can take 24 hours for a pair of them on a 24V trolling motor. For off-grid you'll normally have higher charge rates than that. So set absorb to 15.0 volts and once it reaches that, absorb for an hour then drop to float. You should have SG around that 1.220-1.230 range. You can adjust your time in absorb to get the proper SG.
EQ once a month to 15.5-15.7 at about 2 amps equals the cells out so they stay healthy.
They are lead-calcium plate, designed to take heavy vibration or pounding in marine applications. So they do not have the capacity to hold their voltage at levels of discharge much below 70% SOC. Under load from 70-50% SOC their voltage will rapidly drop to 10.8-11.0 volts, which is no problem for 24V trolling motors with them in series, but can be a problem for inverters. So keep that in mind, as they will start cycling your low voltage cutoff on your inverter if they get below 70% SOC at more than their 20hr rate of discharge. To compensate for that, just add a couple batteries. They are cheap compared to lead-antimony off-grid solar batteries, so you can buy four of 'em for less money than two so-called "off-grid" power batteries
I've got some of those around here in stuff that are 8 years old and still working fine, although they do drop voltage faster than they used on the inverter in the camper if we run the microwave on inverter power.