Ex/Ex means the airplane can only be operated to/at/from airshows. I believe each flight and plan must be submitted and approved in advance by the FAA.
Most
BD-10's were recips -- that was the big point to the
BD-10 was how cheap they would be. The fact that the engine never materialized is a major factor in what killed off the
BD-10.
I think only a couple were modified to jet power, and I don't know how much they actually flew.
Steve