but according to the EZ, Gemini is a Derse sign? wouldn't Sollux's "main" dream moon be Derse because that's what his sign says?

… Huh that’s true- Well, wait, no. Okay yeah given the 6-6 division Ectobiologically, he does fall under the Derse category, and when kissed he wakes up on Derse as his first Life, arguably his Main one. Howeverrrr, he woke up on Prospit first, which is why I called that his ‘main’ moon without any other consideration.