I would guess LEA will operate the Mustang two crew, preferably both type rated.
BUT the Mustang weighs less than the JAR 25 minima (5700kgs) so no unfreezing of one's frozen ATPL on this baby! I presume it will be treated just like the C525 series. Whereby, if the company AOC requires two type rated crew, multi crew time can be logged but an ATPL LST would still have to be done on a JAR 25 airplane! How silly is that!!
Sometimes I wish we could go back to the UK/CAA licences which were more akin to the FAA system.