Maybe there are other ways, but I'm no ML developer so...
For sure, but they require very advanced reverse engineering skills. This one is an unicorn that I know for sure it can be done, but Canon code for sampling the sensor is so complex that it's well beyond my understanding. I'm still researching it, but it can take anywhere between a few days and a few (or maybe more) years, because I'm pretty much clueless about where to start (besides the well-known keywords ADTG, CMOS and ENGIO).
Regarding powersave, it's not the display that eats most of the power, but the sensor in LiveView. And, of course, you need to turn it on in order to take the silent pictures. Sure, it can be optimized, but I doubt the battery savings will be significant for this scenario.
Besides this, powersaving is one of those features that nobody notices when it's completely broken for months (it was not working at all since March 09, and I've fixed it the day before yesterday
, when a related a related issue
was reported). I could not find the exact issue reported in the tracker, and from this I can only conclude that nobody will miss this feature if I'll remove it.