I suppose that makes more sense than them just frying on the spot (which is what I’ve heard about FWR power supplies.)
Now that begs the question, if you power a newer Simplex device off an FWR power supply, will it still be damaged and eventually fail even if you no longer power it with FWR? In other words, if you power it only once with FWR, but power it all subsequent times with filtered DC, will the signal die?