I can't agree weight is irrelevant on an ebike.
A few grammes difference is not important between one mirror or another.
But putting several heavy accessories on an ebike will see the weight mount up, and it will have an impact on handling (on and off the bike), responsiveness, and battery range.
Yes, you have a point of course. When I first started ebiking a few years ago I tried the 'usual' market-leaders in mirrors like Mirrcycle, and the elegant Busch and Muller long-stem version. Some broke with rough-ish handling (that's life in London's hurly-burly), some didn't - but they all, bar none, vibrated!
I had a look at the Halcyon mirror, and must say that as well as its much larger (and thus better) image, it WAS the weight that appealed to me. And lo and behold, mounted on the end of first my Wisper's bars, and more recently on my Dave-designed one-off, vibrate it does NOT. Steady as a rock.
And to repeat what I believe to be an essential safety point: using such a mirror, big as it is, means that when you DO need an instant glance behind, it is there, ready - on smaller mirrors there MUST be a split-second wasted in locating the mirror's image in your field of view.
Might be wrong, of course; perhaps it's just justification for my odd buying choices, but I'm no judge!
Al
ps sorry, oldtom, to further upset your digestion.