1. no, probably same as the HMI capability
2. no
3. forwarding and giving access to necesaary capabilities
4. it does not
See page 18: https://developer.apple.com/carplay/documentation/CarPlay-Ap...
It does however both surprise and annoy me that a cable is required for running this in 2024 which is the reason to why I personally never use it.
And that page 18 seems to have nothing to do with the car manufacturer.
(Without any data to support,) I believe it to be a complexity of map issue (maybe causing a buffer overflow) rather than an RF/WiFi interference issue. It seems far too repeatable for it to be an RF issue.