The same way you get it using TC, by adjusting the power delivered - TC works by regulating the power until you achieve a stable temp, You CAN find a good vape with Power mode - after all you only need the ONE decent puff, Replay then repeats the parameters - presumably the power and temperature fluctuations of that particular vape are repeated - I haven't seen any traces or graphs of power output in replay mode yet.
I can tell you it seems to work well - I've been fighting a losing battle Witha Kayfun Prime running an 80% VG juice in TC mode, Tried it today in Replay, seems to be working really well - better than I was getting with the TC mode...