interesting question - because I wondered that the other day as well as I am starting an F trip ex OSL later in the year.
I suspect the answer is 'no'. I haven't started any ex EU F trips connecting via LHR and I don't think outstations would have generally have been supplied with the relatively new F tags. KIV, if the system works, it'll be the bar-code that should influence how your bag is loaded. In all other 99% of circumstances, the priority (red or yellow) tags make little difference....
if you make me a good offer, I'll sell you a second-hand yellow bag tag