I find boards that don't let you control wattage in temp mode to be basically useless.. you have to set the temp much lower and take much shorter hits..that's my experience anyway.. Setting anywhere up to 230 celsius or 440 faranheit let's you take long nice draws.. if I set it at that temp though, with nickel coils, on a board like a kanger 80 watt that doesn't have wattage control, it will be awful and hot.. by having a maximum wattage setting, you can control the temp even more, I find, as well as the length of the draw..
(I have tested multiple boards without watt/joules control in TC mode, and they all fail for me personally, unless I am using some ridiculous high wattage SS coil, then it's ok.. one thing to note, all of these boards tend to try and apply the full power capabilities till the temp is reached, then they start to regulate the wattage.. by setting a lower maximum in boards that allow it, you can stop this from happening).
when i can set the wattage, i do get the initial hit then of course the board starts to control it going lower and lower).. it's very interesting to watch all TC boards fluctuate the wattage during the draw.. i sometimes fire it for a few seconds without inhaling so i can observe the screen and see what it's doing.
My settings if anyone is curious, for tootling..
430 F across the board
SS joyetech coils, 20 watts
Nickel mini triton coil, 20 watts
vaporshark nickel Nautilus 0.3 coil, 14.3 - 17.0 watts depending on the juice