Exactly. That is why your original question was wrong. It required further knowledge before any answer given could illuminate.
For some time now, I've said I prefer a warm signature. While this is still true, I have come to learn that I enjoy good treble, with extension and sparkle. I still like my bass big, blooming, and warm throughout the presentation, but I enjoy a highly capable treble to add light and air to the stage.
I don't know how sensitive I am to harsh treble. I imagine I'm somewhere in the middle. I like my treble bright, but I don't want it to hurt me. And I certainly don't want sibilance. Some folk find the Kaiser Encore to be harsh. I find it's highs a bit aggressive, but clean and honest.
Jupiter's upper range has more air and sparkle than Dorado. Maybe a little more than UM Merlin. It's signature reminds me most of Encore. Maybe a little warmer as a whole.
None of this will tell you for sure whether or not you'll find the highs unpleasant. Yet I found nothing remotely offensive in them.
PS. My impressions are after a good 48 hours of burn-in, running pink noise.