Oh Jeeze, you think hot loads are noisy, distracting, and take extra time? And now you say you start up when they're "under the disk" and obviously completing the loading thereafter? Like that whine and belch of fumey gas, building to a crescendo of shriek and whir, isn't distracting? And them without their helmets yet, probably, with you giving them a good dose of hearing impairment from thundering decibels?? Give me a break, Pal.
Look, you do what you want. I couldn't care less. Our competitors in the area flying singles usually shut down, I've noticed; we, in our twin, don't. I'm sure they think we're wrong, just like we think they're wrong. I almost always beat them to the hospital, though, and that's what counts for me. It doesn't seem to make any impression on them, but hey, I guess not everybody has situational awareness and/or learns from experience...
It's only better not to shut down one time, and that's the time that you won't be able to get it started again...and, since we can't tell which time is "that time," for me, the solution is obvious: Keep the damned thing running at scenes unless there's a pressing reason not to. But you do what you want there, Buckaroo.
The crews are trained and briefed to do hot loads (at least ours are...), they've done them many times, they know how to do their job, let them do it. I'll do MY job, keep the damned thing running and ready to go and increase my chances of being able to get back off and complete the trip--and yes, decrease my time on scene, because no matter how you slice it, a hot load is faster.