I haven't been highside in almost a year now so I don't purport to know the actual operation behind this, BUT I would place my money on testing surveillance systems and on-device tracking modules. CDAO has been investing very publicly in these areas alongside the Maven program and TF Lima. They need a lot of good data on populated areas to make this work; they also can't risk testing this in warzones where a downed drone will both [1] leak advances in technology we have made since Reapers and [2] expose the on-device models they have in place. Could even be a vendor trying to evaluate their models; there is nothing particularly illegal about these drones.