Technically both @KenD & @Anthony_Vapes are right in that there really is no way to know for sure what temp we are at no matter what mod you use including a DNAs without calibrating it properly. DNAs tend to be closer than other mods to a true temp, but differences in wire metallurgy and other factors cannot guarantee accuracy without thermocouples in coils. Hohmtech mods you have no way of actually knowing you are close without comparing it to a dna or doing a water test. Even thermocouples can become inaccurate due to improper calibration.
A good way to get things as close as possible is to set up your build, and use water on a saturated wick to insure it boils @ 212f or 100c and adjust the TCR or FSK% until the mod reads correctly at 212f or 100c from a calibration standpoint before rewicking using it with you juice.
Is it a PIA that no one wants to bother with - YES! But it is the only way I can think of to be reasonably sure your mod is properly calibrated to temp for your build no matter what mod you use. It is important that we all understand the risks and how to manage them IMHO.
Professional tech buyer (ret) here. Right on point. Thank you.
Good luck.