Actually, I found my SPG’s to always read higher than my transmitters (~75-100 psi higher), especially as the PSI readings get lower on the scale - I trust my transmitters to be more accurate across the range (they read within 5-10 psi of each other).There was no inaccurate SPG reading in your account, which had fueled my earlier response; and a broken gauge simply requires a replacement (I carry several); and that spool issue required little more than an adjustable wrench; some grease; and a piece which costs less than 2.00 in a save-a-dive kit; that and less than five minutes.
Over the years, I have had various electronic equipment failures (the earlier computers really sucked); but none that have ever required aborted dives, since I carried analogue back-up.
Your faultless record with transmitters just recalls an old saying among motorcyclists: there are those who have been down and those who will go down . . .
I also fully expect that I could have a transmitter failure at some point which is why I have the redundancy - my point was to convey my experience as you seemed to suggest electronics were more prone to issues (also based on you experience) while my experience has been just the opposite - my electronics have been less problematic!