I am not sure of your prime focus set-up but my DOB had the same problem.
I was able to fix this but not sure if your reflector will have the same adaptor.
Here is the guff, I can't take a photo of my camera setup because the camera used for the set-up
nice to have a second camera.
My SW can unscrew the 1.25in adpator to leave a T-thread. I then purchaced only the EOS to T thread adaptor -
https://www.bintelshop.com.au/Product.aspx?ID=5551 and was able to screw it directly into the 1.25in adaptor.
It give me an extra 1" available for prime focus adjustment.
I can't say this would work for you but never know.
