Wow that quite the telescope! This is basically what i wanted to build just smaller and and with a Reflector scope instead of a Refactor scope, thank you very much for this informative comment :D

thats what i was thinking :/

Tubeless telescopes exist tho, i saw some big diy newtonians that did not have any

entrance pupil isn’t well defined

oh right, i didnt thought about that, maybe i could add some sort of shroud to the light inlet

I already ordered a first surface mirror to test, i will report my findings :D