m28 only makes sense imo if you run a poseidon ccr
Sure, but I only have occasional CCR opportunities nowadays -- which is about as spontaneous as organizing a space shot -- due, in part, to rebreather complexity and the travel limitations posed by the covidiocy -- quite unlike the load of conventional dive gear, stored behind the seat of my truck -- wet and ready within minutes; and the M28 does have a decent open circuit setting.
Otherwise, it would just serve as a paperweight, through a good deal of 2020 . . .