Alex, for example, spikes the heat gauge up dramatically, by 5's and 10's instead of gradual ticks, for instance. (There is no math involved in this, I'm just approximating to give a picturesque ideal.) So if she throws and enormous arc of lightning and shoots her gauge immediately to 40 heat, it's going to take longer to cool down. If she throws another one, before she is totally recovered, then it spikes up even higher, and so forth.
Nomad's skills are more continual low-burn effects, and so she'd tick up 1 or 2 points a minute in order to maintain her blades, but since she'd also be acting athletically during this time she'd probably be upto 60 after about 10 minutes of active combat.
Her huntress upbringing would've conditioned her body well for such an active lifestyle and her experience with her abilities would allow her to hone the control to a significant level. However she's not really spent the time to explore the range of her powers, sticking to mastering a few tricks rather than trying to develop new techniques, and so she still has quite a lot of room for development.
At some point (depending on Nomad's development and consistent to the on-going plot) she'll also trigger her full awakened state, allowing her to convert her entire body to water for short periods of time, making her functionally invulnerable to physical attacks, while at the same time increasing her vulnerability to extreme temperatures and electrical attacks.
Just to check, has Nomad been accepted with the
changes now, or is there anything else which needs to be verified?