In regard to HC-110: I don't know what time frame you have in mind, but the concentrate we have today is definitely less viscous than the HC-110 of twenty or twenty-five years ago. Incidentally, it has also lost the strong odor of the earlier stuff. Does anyone else remember the incredibly putrid smell it had back in the seventies or early eighties?
You're absolutely correct about diluting directly from the concentrate. I don't know if it really makes any difference, but I shake and swirl the concentrate a little just before pouring out the small quantitiy for mixing. Stuck to a darkroom cabinet, I also have a small laminated card listing the various dilutions.
I much prefer T-Max developer for T-100 and T-400, but if you were forced to limit yourself to only one developer for almost any kind of film, the HC-110 would serve well.