Incidentally, it occurs to me I assumed the 4.7k resistor would run to infinite resistance if it fails. I did verify it before soldering and do periodically check it but it would be nice to know if I'm right on that. (!)
If you look up 'GoFlow'
I suppose a pair of resisitors in parrellel would be best
There's nothing wrong with series, though if one resistor fails open everything stops. (Kind of the point I know but inconvenient.) If in parallel one fails short the total impedance is still the average of the two, right? So twice as much current flows rather than thousands of times as much. Since the "safe" current range presently extends more than two orders of magnitude from the minimum useful value a factor of two increase isn't much.