Do you know which changes require a new profile (going straight from vanilla to the 2.0 version)?
Everything that is not in the database will work, like AI agresion, AI overtake, Wet pace optional abilityes, car tunning files and all that will work.
The things in the database is not so sure about, most of them will work. Like safety car that will work without starting a newone. AI driver changes I think wil work, and tyres for the last races.
But on things like team performance, there im not so sure. I dont have any old profiles I can test all myself on, but what I have seen other people that can test it, some say it will work some say not..
So a summary of what I know: ALL changes that are not in database will 100% sure work, Database changes will most work, but something not sure about, but if team performance also work, then you should have the most important things without new save. Just continue youre career and see whats its like, one thing is 100% sure, that there is no problem in continue when it comes to corrupt save and all that