To further cloud the battery-charging issues, a previous version of the technical data sheets from East Penn/Deka for their Pure Lead series of AGM batteries disclosed that there was no limit on current for charging and experiments to induce thermal runaway were for naught. I wished I still had those data sheets (I still have the batteries) as the experimental charging parameters were torturous.
Be advised, though, this information was about the Pure Lead series of AGM's from a few years back and they may not be available or have changed construction schedules/models since then.