Today I received a phone call from customer relations (pleasant lady) who was extremely apologetic for having given me the wrong information regarding GS/ GS F vehicles.
She had, upon reading my reply with a screen shot of the official Lexus list showing vehicles at risk, gone back to the Technical Team who checked again (apparently due to both cars having cherished plates they checked against vin numbers this time) and have agreed that the GS F cars are at risk but the hybrids are not due to being built on the different global architecture.
The good news for me because of this being wrongly informed, as a good will gesture they will fit a tracker and geo fence to the 300h as well as the F.
So to clarify.
GS F is sanctioned for security upgrade.
Hybrids are not sanctioned (except for mine).
Apparently dealers are aware of the models concerned and GS F owners should book in with their preferred dealer to get the ball rolling for fitment of the security enhancements.
I
Duggie B's post in GS 300h 2018 & GSF 2019 canbus theft risk was marked as the answer