what happened to double-source FETs with current sensing? we just learned that those exist and they seem really useful; the sense source has a defined proportion of the area of the power source, so you know that it'll get an exact proportion of the current to within manufacturing tolerances--so you can use a simple current sense circuit that only needs to handle 1/100 your actual output current
but no one seems to make them anymore, they're all marked obsolete on digikey
-F