Using it in the automatic program will probably consume less energy. Users are typically less good about switching in and out of manual programs than the automatic program is at switching. And above posters are correct that it will flip in and out of the program, so the hours is actually a fair bit.
I’ve had users sit in the speech in loud noise all day and that sucks the battery twice as fast anyway. I think it’s reasonable for phonak to be transparent about effects of processing on battery life.
At this point, I can’t see a difference between the I90 and the I70 sphere programs.