Interesting challenge, going to substantially wider Q-factor. I will not be of much help. I'm of the as-narrow-as-possible type. (My knees do not like wide Q-factors at all and have never seen too narrow. A bike they love is my latest fix gear with a narrow Phil Wood BB, set up asymmetrical for chainline on the right and crank close to the chainstay on the left. I do my best to stay away from Shimano cranks and look for older Sugino cranks because they are straighter with smaller clearances to chain and chainstay.
We all have to find what works of us. I love seeing the creativity people use to meet that need.
Ben