It is doable, but requires some handwork. I have done it.
I can race (got the pitstops working) and run TT. Somehow I haven't been able to get the system save laptimes in TT or to save/load settings in TT or race. I am not sure, if I am allowed to talk here how I did the transfer, but it wasn't a direct copy-paste and you need to use the modding tools. Here is a a screenshot with RB on the main straight, see Karthikeyan is last and Webber is catching the 22nd.