With the revamp of the engine designer, there will be the possibility to choose a some sort of system to control continuously the valves (like Fiat Multiair)?
I think it can be implemented in the VVL choose on family tab, then in the Top end tab you can choose the min and max valve opening profile (with the existing slider) and in the VVT space you can choose if you want to optimize the efficiency of the performance of the engine.
There are nuanced differences between the various VVT and VVL systems, yes. What you want is what we consider to be a modern VVL + VVT (all valves) combination and I would argue that the game covers that nicely already. Anything beyond that is so niche it is not worth considering at the moment.