Short meta-topic question: are you all professional opticians? What does it take for a non-optician amateur astronomer to contribute meaningfully to such a discussion?
A few of us have experience in professional experience but certainly not everybody. To name a few from whom I know they have it or strongly suspect they have it: Mike I. Jones, Ed Jones, Oregon-raybender, Vla, Mark Cowan, An18, me. Someone else like MKV has read quite a lot in the field of optics and optical testing but I happen to know that he has no professional experience.
How you can contribute, simple: read some advanced books about optics, do not hesitate to ask questions and certainly do not hesitate to make more advanced designs if you feel you like them more. The problem is that a lot of ATMs build "only" Dobson/Newtonian telescopes. They make nice looking ones and since so many examples exist online, it is easy to find examples, spreadsheets, books, CAD-files etc. of these telescopes. There is a myriad of examples you can take your inspiration from. If you have difficulty judging and evaluating the designs above, read books like Telescope Optics, evaluation and design as a starter. For me that book was a great stepup to professional optics and it was also written with that intention.
Last of all: Do not hesitate to ask questions. Let me share a personal anecdote: When I was ATMing as a high school student about 20 years ago, I learned how to grind and polish optics. I learned it from a guy but I noticed that he circumvented the more difficult questions. At the same time, I was in a e-mail newsgroup with amateur astronomers and Harrie Rutten (the author of Telescope Optics) was in there as well. He regularly contributed to the newsgroup. I met him, give or take a few days, exactly 21 years ago we got along very well. I never hesitated to ask him questions up to the point that some members in the newsgroup became annoyed at me that I asked so many questions. But boy, I learned a lot from him.
If you feel ashamed of asking questions, you shouldn't in the first place, but you can also send a PM to the writer of a post. If that doesn't work: feel free to PM me. Am often willing to answer questions.