I have bill’s files. I always thought they were a little too extreme in colors for this task and depending on which profile you use the results are extremely variable, but I’m sure it does force ink out of every nozzle which is the main objective. As you mentioned, my target specifically targeted Epson’s inkset that uses orange and green inks and I found I had to force more of those colors than I thought to get enough through those channels. It seems to work fine with other printers thought, the orange and green in the file just exercise a few of the colors a little more.
I messed with with my file quite a bit to try and use a similar amount of each color when it is printed. I used Epsons status page which shows ink consumed by color the last 9 or 10 jobs to try and fine tune it. It’s not super accurate, but it does a fair job.
I assume Canon has a similar utility, but I haven’t used a canon printer in such a long time. I’ve always heard with a canon if you just leave the printer on it will do a pretty good job of keeping the nozzles clear. (I had good results with that when I was using an ipf6100) Power consumption when left on is minimal, maybe even less than the power up requirements every couple of days. But heads are expensive on the Canon, and they eventually will die ... and will do so much faster if not cared for. Kudos for recognizing that and trying to take care of them.