Meh, I don't use mine above 60 watts or 50 Joules and I only use the .25Ω kanthal heads or the .15Ω Ni20 heads (so you should be golden with the .5Ω). Maybe it's because I use mine on an SXmini M-Class with the POWERFU+ setting, but I tried my tank up to 100 watts on other higher-power mods and it tasted no better; frankly, for me, it was more nuanced and enjoyable at 60 watts of no-ramp-time power. Otherwise it was just slow-to-heat, then it got hot and the extra heat provided no extra revelation to the flavor I was vaping. Your experiences may be different, but I wanted to post since the common refrain seemed to be "go higher". It's not wrong per se, just not written in stone.
And let me be the one of the few that says the Ni200 coils for this tank have just supplanted the kanthal heads. Absolutely in love and no higher than 50 J (and 450 F)! Could I use it higher? Sure. Do I need to, to be utterly satisfied? Hell no!