Its been tested by now, Ive looked into it a little. Seems like 90% of the time contrails form inside clouds and there is no benefit in avoiding them there. So simply avoiding contrails altogether is not recommended, but avoiding the ones forming in a clear sky would be pretty easy and extremely efficient warming-wise.

Upvotes matter in the sense that comments with negative upvotes get dismissed more easily without thinking about them. Less people would watch a video from a comment with -5 votes than one with +100.