This has been bugging me all weekend and I still have not found an answer to fix it.
The problem is because the iteration which you want to replace is still there, cut list is not functioning.
The fading iteration is just being placed on top of the existing one.
I think you need to build the iterations with a different method or maybe someone else can figure it out.
When we get the ability to export FFGL effects/Fxplugs I think it could be a good idea to pool our efforts and sell them (and give them away if desired) from a store page here at Vuo.
It would drive some traffic towards the website and show the potential of Vuo to a wide audience.
We could possibly agree a commission with the team to help with further development.
It might save us from repeating our work and help avoid any potential issues with using shared compositions and utilising each others work.