How many K40's I have that have "opened up" the tuning capacitor at any time? NONE, and I do run a little heat and own several K40's.
So your protestations of capacitors failing at random is nonsense!
Yes K40's are a little antiquated, they just work as long as you don't overdrive them.
99% of the people on this forum would agree with me..........didn't know I was protesting, just stating first hand experiences.