Honestly i tried a 30w for the fun of it on my build - 1.3 ohm single coil on my kayfun lite v2........the RBA exterior gets hot way faster than I was at 15w to 18w, heat conduction of course....I got a hot vape at 30w than my 15wish, cloud quality almost the same but flavor lose out to the 15wish setting however not saying 30w is no good but individual preferences. I guess if I use my AgA t5 with afc my coil build will be of a larger surface area, more wick and maybe higher ohm coil and than at higher wattage, it will be a difference experience. The latter is yet to be build or tested.
Cheers!