The assymetrical offset (not sure what else to call it) is a solution to get the axes of two 150mm objectives within the IPD of the user. If that doesn't make sense I can do up a sketch which explains the concept much better. The secondary mirrors being different sizes won't make a difference in illumination. One intersects the light cone earlier than the other, so the size difference is just a product of where on the cone it hits. Again, a sketch explains this better. That is for the refractor bino box you see n that link. Yes, a larger secondary will effect the illumination of my newt design, but it should be fairly inconsequential in real world use.
When do I plan to do it? Probably next year...maybe??? Definitly hoping to try for it before graduation. Won't be this year though. I have to rebuild the deck, and promised that I'd revamp the upstairs bathrooms before building another scope. Have to have balance.