An Optima will survive auto-audio abuse better than a lead battery, but doesn't stop flicker or really discharge faster. A 1 farad stiffy cap will provide momentary bursts of increased current, and should fix it if just running one amp that is fused at 50 amps or less. The cap isn't going to help for more than a few minutes if the battery is half dead because the alternator can't replace the current the amp is drawing, from say a longer cruise. Same for a 2nd battery. The only real answer is entering the scary, expensive world of custom alternators, dual alts, smaller pulleys... ugh just get the cap, and keep the leads Short, less than 14-16 inches.
