Standard explanation I tell anyone getting into rebuilding, don't jump off the cliff to the deep water below head first. Start at a higher resistance to practice, then after a couple weeks take a step down, going down gradually. Never know if a wire connection becomes loose, a hard short, errant short, or any other number of factors, this learning stage helps you troubleshoot any potential iteration of Murphy's Law. 0.8 to 0.5 is generally pretty safe learning territory, also the Coolfire is a regulated mod, unlike a mechanical where the coil is your output throttle, regulated you can build higher and get better performance, unless on a mech, the days of the lower you build the better the performance do not apply as much anymore.
Building to low is wrestling with a large fire breathing dragon, not done properly or safely, you will get burned or have a close call.