I think the Air France cadet programme has several entry points depending on what stage of training you are at and I don't believe they necessarily view more advanced training as either an advantage or disadvantage. The only point at which I don't think you can apply for their programme is if you have started an MCC/JOC because upon completing one you become eligible for their newly-qualified pilot entry point. Quite a clever system if you ask me.
One point I think is worth making is that with these "fully-funded" cadet programmes you are still paying for your own training through having a reduced salary, for example I believe the TUI programme has a base salary of £32k for four years. Compared with a direct entry salary, you are £18k down, the difference once you move from SO to FO is something like £25 according to PPJN. If you've already started it may simply be worth seeing it through to get that higher starting salary.