Siddhat, I recommend you google and read up on as many technical articles about VRLA batteries as you can, including from large battery manufacturers that include operating instructions for their batteries.
That way you will gain some experience about what variety of charge profiles may be being recommended by different manufacturers, and for what applications (eg. standby, UPS, cycling, intermittent charging, PV, traction, anything and everything in between).
Then read some operating manuals of a few commercial chargers to get a feel for how they approach the topic - some provide a list of different charge profiles with the ability to set parameters associated with various stages within a profile.
The information is all out there.
Also note that a charger must only allow output current to flow in one direction, and many chargers use a series diode to enforce that spec. So if your charger changes its command level for output voltage from say 14V to 13V, then initially the charging current will fall to zero as the battery voltage relaxes back to its open-circuit voltage level. Assuming 13V is still above the OCV then at some time the charger current will start to increase from zero again. So you need to read up on OCV and how that changes, and look at charge discharge voltage curves, and discussion about the chemistry of that type of battery, and look for some experimental graphs of voltage and time.