Thank you. That comforts me a little. So the exchange has nothing to do with your seed (since you have to enter the pin before the seed anyway) and after it gets the pin and before it gets the seed it has no outside connection to the world again?
Correct. The only thing the pin+exchange is used for is to temporarily load the decryption key into the devices RAM. At no point is your seed - either in encrypted or decrypted form - ever off the device.
Thank you. That comforts me a little. So the exchange has nothing to do with your seed (since you have to enter the pin before the seed anyway) and after it gets the pin and before it gets the seed it has no outside connection to the world again?