Condensation in Speedmaster

Since you mentioned you are in Southern California, I'd be interested to learn which two boutiques are involved, so I can avoid the first one...

And it's amazing (in a bad way) that people still repeat the nonsense about 5 atmosphere water resistance being insufficient for washing your hands.

Where are these people sprouting this nonsense about the 5 atmosphere water resistance being insufficient for washing your hands?
I believe it's sufficient when the watch is in perfect condition.
It's just that with time and daily life, that water resistance rating becomes meaningless in an ever diminishing fashion until it potentially becomes near impossible for a reputable watchmaker of any persuasion to guarantee that 5 atmosphere water resistance to hold for the period between services, even following a fresh service.
Even for a like new watch, should it be damaged in some manner which is not necessarily apparent by casual inspection, it may have compromised water resistance.
This is a fact of life unless the watch is looked after to the highest standard.
All these watches are water resistant up to a point, until they are not.

See, that's the thing with it.
What is a reasonable period?
I'm sure most of us would agree that the full period between services would be reasonable, generally speaking.
However there are so many variables, such as how long between services as an example baseline?
Then the consensus within the industry is that a dive watch used for it's intended purpose should be pressure tested every year as best practice while some divers may opt for every 2 years.
The risk has to be managed by the owner as they see fit.