Well the everstart should be a lead acid battery, Which shouldn’t really matter how you charge it, so if you set the battery charger to AGM or gel battery (probably the same setting) the Lead acid will be fine. The issue is with the Gel cell, even a little with the AGM too, if you charge them too hard and too fast you will develope bubbles in the Gel material, and lose contact with the metal in the battery, and probably won’t get it back, so you end up ruining the battery. The Gel/AGM setting charges a little slower to prevent this, from what I understand.
The lead acid will just bubble up and be fine, so if you have to choose only one setting choose a setting for the Gel or AGM battery, the acid one will be fine.
Seems like there are some benefits to running Gel or AGM, (I’d prefere AGM myself) So the choice is yours when you replace them, Some say the last longer both in use and in years, I choose to replace mine (lead acid) more often and save some up front. From my experince the Lead acid have been great by me.
BTW the Optima’s a gel cells, different than the lead acid everstart…