You are overthinking it. There is no need to earn a PhD in exercise physiology or carry a dozen gels and electrolyte tablets standing on the starting line to race well.
Gels (any kind of rapidly ingested energy basically) will definitely help if used sparingly and only during a race.
The trick is to train consistently with no refuelling whatsoever (no carbs-no electrolytes-no caffeine). This is easier and better practiced during early morning runs of course. THEN take a gel or a few sips of carb drink on the latter stages of a marathon/long race. The difference in performance is notable.
Maybe there is a more effective way to use refuelling to your advantage but for 99,98% of runners there are more important issues to deal with before starting to worry too much about metabolic pathways.
Source: just me, a hobby jogger who trains on empty for the last 13 years and only takes a caffeine gel after mile 16 in races.