Something new and untested being done regarding voter registration and eligibility DURING an election? What a great entry point for FUD. I'm sure foreign and domestic malicious actors won't use this confusion as an excuse to disregard the outcome of an unfavorable election. That would be against the rules.
in which U.S. personnel with security clearances supervise foreign engineers, including those in China.
From the security clearance perspective there really isn't any difference between China based engineers, Chinese spies, and Joe America accessing classified code without being cleared by the DoD.
If an individual did this "escort" scheme, they would be arrested.
Slow down there. Keep it reasonable