Temp gauge is good for telling you why it just failed.
I put an N2k pressure gauge on mine. I may put an isolation valve on the telltale as in theory all it now does is spray my aux with brine. Valve because if the electrickery fails I can turn it back on.
And it being off means slightly more coolant for the head...
As an aside I have 2 engines with no telltale. Granted neither have a deadman either...