Perhaps this is too simple (Don’t know why it wouldn’t work. )

if you have one working fob, couldn’t you remove the transponser and glue it onto the back side of the ring (around the ignition) that ties into the SKREEM. if I’m not mistaken, the transponder is only required to get the car started and all set all systems to go. If it’s always next to the SKREEM wouldn’t it solve the problem of second fob?

this way the transponder chip will always be in place and you can use USED OEM with new key or New EBay fobs

The circuit board from any Crossfire fob can be programmed for lock and unlock

interested to hear if anyone has already done this