Both the Provari and Sunbox supply very nice high frequency power so there is no difference in the vape you get from each of those. The Sunbox will supply 20 watts which is more than the Provari will. You didn't mention what voltage or wattage you set for each of your devices, but that will certainly affect performance and different devices can require different power settings to be optimal.
The issue is with the toppers. I don't have a Cyclone or A6. The Kayfun produces excellent flavor, better than I can get from my IGO-L which is the same type of RDA as yours. I can't comment on throat hit because I have not vaped nic juice in it yet, but I'll take your word on it performing very well there.
I run dual coils in a Trident clone and that produces massive vapor and TH. It's not as refined in taste as the Kayfun though, specially the way I set it up. I use micro coils with cotton at about 0.5 ohms combined, so about 25 watts. The two air holes stock are about 1.8 mm diameter each and I find those adequate.
The IGO is set up with a micro coil at about 0.8 ohms with cotton, about 16 watts. I drilled the air hole to 2 mm. It does everything well, but nothing exceptional. It does produce very good TH but not the same as the Trident. Flavor from the Kayfun is better.
I think you can get more TH from your RDAs and probably better flavor too. I use mechanical mods for my RBA/RDA's so I can't adjust power on the fly. The resistance I build my coils at is what sets the power, or watts, they will make. You don't have to go so low in resistance because you can adjust your power supplies. From your pictures I think your coils are bigger in diameter than what I think of as micro coils. I would try 1.5 mm inside diameter and be careful not to put too much cotton in them as that will choke the wick and performance drops immediately. Yours look good the way they are, just thought I would mention it. I would also use much less cotton outside the coil.
Air hole placement is important too. Air flow right on the coil will give you the best flavor and vapor production. Turn the cap a bit to get the air holes off the coils and TH increases. Air holes also need to be the right size. Too small and you don't get enough air flow on the coil so they heat up more and the vape becomes warmer. The more power you put on the coil, the bigger the air holes need to be. IMO, the stock ~ 1.5 mm holes are typically good to about 15 watts, but that is a personal thing.
