RE: Ever had a problem when swapping crystals?
Please understand, people, that this is currently a non-issue for the FCC. How about a closely related example of when the FCC does care? Back in 1997 when FRS radios started turning up, a few manufacturers included externally-removable antennas on their radios. It was determined that this was in conflict with the FCC regs and the manufacturers were forced to use only non-detachable antennas. (or no type acceptance!) Now you WILL NOT find newly manufactured FRS radios with detachable antennas. Or how about the Audiovox GPS/GMRS radio that came out a couple of years ago (not talking about the Garmin version here). A group of concerned GMRS users pointed out to the FCC that data transmission were not allowed on GMRS frequencies. Audiovox was promptly forced to discontinue sales of the radio.
When the FCC feels that something is not in compliance with their regulations, they withdraw their type acceptance, forcing the manufacturer comply. If they told futaba that their externally mounted xtal was jeopardizing their type acceptance I guarantee Futaba would find a way to comply. It wouldn't break their back to hard-mount the xtal on the PCB and cover it up with a tab.
The truth is that the FCC does not see user-changeable xtals as a violation of their regulations or they would have stopped granting type acceptances long ago.