An articulated rationale for why a fork would go a long way for awareness of why an existing user of Helix might consider to use Mitos instead (or not) really needs to be the first thing we see on the front page of the site for Mitos.

One thing that really sticks out to me and gives me a feeling I won't consider to use Mitos, is the presentation further down on Mitos' front page of rendering of image files inside the terminal emulator. I rather that an image viewing program be opened, maybe called with options to not display interface widgets, and to be displayed in a new window tab. I use i3 or Sway, so I already have macros that do just this, and I don't fail to appreciate that others have this luxury (or not).

Alternative branches, or even forks like this are a good thing. Sometimes these help reach new consensus and merge back into the original project making the new project stronger, provided the original reason for a fork wasn't really issues of conflicting personalities.

I think a fork of Helix can be a step in the right direction. But "view images inside the terminal" doesn't pass the smell test. The mindset of displaying images inside of a terminal window and the macOS window decorations in the example screenshots, those two things together are part and parcel.