Hi, I bought soe for the q1 he, but it's a bit too long, so since the q3 he is longer, it should actually fit perfectly

The Palm Rest fits my Q3 Max (a dream...) perfectly. The Q3 HE is, as I understand it, the same aluminium case, but with Hall-effect switches (presumably the continuation dream...). So same case width and height (see also information at Keychron or Digitec), so it should fit. And yes, for me this silicone cover fits better than the wooden cover I also have (which is less comfortable and a little warped, but - I have to be honest - clearly prettier).