I've had 3 oil pressure senders fail, (see archives).
And yes, long brass fittings *will* snap off eventually. Not one of mine, since I took the advice of the seasoned successful racer who advised me to 'fix it or lose it'. You can websearch yourself if you want to, plenty of forums like this, of folks that it did happen to. (Why would they lie about it?)
It's been stated on this thread that engines can run 'for hours' with no oil, and that drag racers 'do it all the time'.
Were these Spitfire engines? And was that with 'no oil' or 'not much oil left in the sump'? And what is meant by 'running'?
A Spit motor with a completely spun #3 conrod bearing will startup and 'run'. Sure, there's an awful noise, the motor shake like mad, won't turn over 3,000 RPM, lot's of smelly smoke, plus the bearing shell is melted, the crank journal scored beyond repair, and the conrod ruined, but hey, it 'runs'.
As a Spitfire owner for 35 years, and an ex-racer, I've had, and seen, my share of motor blow-ups. I never had a 'magic Spitfire' that would run without oil.
And as for drag racers, let's see, they run about 1/4 mile, then routinely tear down the motor, right? And their crank journals are nitrided too? And replacing engine components is standard weekly (daily) procedure?
C'mon folks, get real. If you lose your oil in a Spitfire, then you are looking at a teardown. Minor if you catch it right away, major otherwise. For most of us, that's a PITA and expense, to be avoided.
At 3,000 RPM, the linear velocity at the conrod journal is about 20 ft/sec. The conrod bearing, flattened out, is a strip of metal about 3/4" wide x 5" long. So imagine dipping this strip in motor oil, placing 250 lbs weight on it, and then dragging it accross a smooth flat steel surface at 20 ft/sec. Oh yeah, and heat it to 250 F first.
Got the picture? How long do you think that strip will last without damage?
So do what you can, to avoid losing your oil:
Capillary tubing from the block to a remote T fitting is just as reliable as the same type of capillary tube direct to the oil pressure guage. The difference is, such a fitting won't break off and spill out *all* your oil.
And as for being 'too complicated' or 'extra work', well, you gotta make that call yourself. I consider unexpectedly breaking down on the road, and having to rebuild my motor as 'complicated extra work'.
I'd much rather spend my time and money doing modifications to my car.