I think I figured out where some of the conspirators must be!
There are many companies (I easily found 14, there must be others) that make GPS receivers.
https://www.mouser.com/
At each of these companies, there are multiple engineers who programmed and debugged their product. These people would be very familiar with the raw data from the satellites and would where the transmitters are or how it is faked if it secretly works completely differently.
If the earth is flat, some of the people at each of these 14 companies know where the transmitters are and how it actually works and so are secret conspirators. If the earth is round, it works exactly the way they say and they are just some engineers.
There are many more than 14 companies. you listed only 14 commercial grade module companies that sell their products in North America. Commercial modules are also sold by other distributors within NA, Such as Digi-key, Arrow, Avnet...Yes they overlap in models, but they also will have exclusive deals with only some distributors. There are also other modules in other countries by other distributors that we would have a lot of trouble searching for, such as China. There are Chinese companies who make Chinese only GPS that we never see. They don't certify them for our market, especially since China now has it's own "Satellite" system that NA GPS devices can't see in the sky. Same goes for the UE satellite system, that we can see on the fringe but not completely. Now, what we were discussing was only commercial grade modules. There are also chipset makers (manufacturers who don't make modules, or only supply the chips that go in the modules). For example, Atmel had a deal in the past with UBLox. Atmel made the chip that was in the Ublox module. Atmel is not a GPS company, but was primarily known as a micro-controller company. Further, these are only commercial grade products. There are also companies that make military and industrial grade only GPS products. Requirements are different in each case. Multiply and add the number Commercial, industrial, Military, chipset, Countries and that number is already in the hundreds easily. And we can keep going...There are also the GPS antenna manufacturers that certainly need engineers who know the truth. Again, they apply to commercial, industrial, military, country....Then there are other companies that you don't realize that make GPS devices. Such as cellular radio manufacturers who include GPS in their modules or chipsets. Telit for example. And again the idea of grade and country applies.
In fact I just looked at your list of modules from Mouser. That list of 14 are not even the main companies in NA. There is an almost completely different list of 25 in Digikey NA.
https://www.digikey.com/products/en/rf-if-and-rfid/rf-receivers/870?k=GPS%20moduleAdd to all this that over time, people age and retire. New people go to school for four years or more to become engineers in the field and then come to find out everything they learnt means nothing and have to learn and study "the truth" before they can begin to work on the products. So they are taught by either the other engineers?...or special secret teachers? They don't just walk in and are told "the truth" and start to work. They would need to know the complete history, the way it works, how it's designed down to the low level. This would apply to not just the HW engineers, but others like SW engineers for example. This re-learning can take 1-2 years per person. Then you have the engineers who design the land based transmitters, the ones who design the balloons...And all the while hoping none of these people open their mouth and take everything to their death bed. And again, this is in all major countries.
I haven't exhausted the amount of people who would need to know "the truth". We are in the tens of thousands since it's inception in the 70's, if not hundreds of thousands. It would not be just a small multiple of the 14 companies you listed.
Not meant to be a rant, just expanding on your argument about the amount of people who would need to know.
PS, just to add, the companies who make GPS test equipment, GPS repeaters, and GPS simulators.