Yep - The devils are in the detail of the specific inverter/charger you have.
As noted, Magnum has AGM 1 setting, which is for Lifeline - and - AGM 2 setting, which is for other AGM's. But depending on how old the inverter is, if it is a Magnum - one that Lifeline made a slight change to their recommended Float value in their Feb, 2017 Tech Manual. So for older Magnum's, you now need to go in and use Custom profile.
http://lifelinebatteries.com/wp-content/uploads/2015/12/6-0101-Rev-E-Lifeline-Technical-Manual.pdf
And I agree with the input that regardless of inverter/charger - refer to Lifeline's recommended values, and set your Charger to as close this as possible. When in doubt, Lifeline has great Tech Support to bounce questions off of...
And also agree with the 8 years with the previous bank was good - so you were doing something right with them.
I'll share that my X's 4 L16's Lifeline's - walked down - due to a mistake I had made. So I replaced them at 5 1/2 years... After working with both Magnum (MS2812) and Lifeline's Tech Support - I've now added a periodic Conditioning regimen to my calendar, as preventative sulfating avoidance maintenance. Every three months, I run a four hour conditioning on them. If I ever detect/test diminished capacity signs - I'll do an 8 hour Conditioning run.
Best of luck to you with the new bank,
Smitty
(Note: A plug for a company that does back their products. Lifeline helped me determine what had happened to my bank, with input from Magnum too. Even though I was 6 months our of warranty - Lifeline made me a great offer of a discount on a replacement bank of the same. They did not need to do this, they could have just points out that I'd had that mistake in their care. Pretty cool in my book!!!) And, they took my old bank back in, to run some further tests on them - to see if the could recover them further then I could. (One out of the 4, was weaker then the other three, which dragged the other three down to that level. I could have limped along for sometime on that existing bank at the diminished capacity. But the offer to replace made it a no brainer:)!)