New business aircraft under Part 25 -- Single Pilot Exemption

[Mach Stall]

I'm very interested as to how difficult it would be to certify a newly designed business aircraft for single-pilot operation under FAR Part 25. (I should stress the question has to do with FAA certifying a new design -- not about trying to get some sort of waiver on an existing airplane).

I assume an exemption would have to be obtained at the time of certification based on current Part 25 regulations. I don't think this has ever been done for a fresh design - does anyone know for certain? I'm wondering about an aircraft just over the 19,000 lbs weight limit for the Part 23 Commuter Category.

I only know of one relevant example historically, but this was not a new model at the time of the certification exemption. Long ago, I think the FAA did grant Cessna operational exemption under Part 25 for its Citation S/II model in what came to be called the "Cessna Exemption" by many, but this was done after-the-fact of Part 25 certification and relying on past safety of Citation models in the argument from Cessna.

Also, it seems pretty relevant to my question that years later, when Cessna had to get a new certification for its CJ series, it did so under Part 23 Commuter Category, arguably suggesting Cessna didn't think it would be a piece-of-cake to get a fresh single-pilot exemption under Part 25.

I'm guessing it would come down to demonstrating pilot workload. If a new aircraft had twin-engine centerline thrust, would this strengthen the case for a Part 25 single-pilot exemption via reduced pilot workload?