I'm still on Arena 6, so apologies if this already exists in 7...
It would be nice to have a global setting for "default envelope" - I personally find Sine In/Out to be much smoother than Linear for the animations I want. Right now, every time I choose an envelope, I have to change the type individually. A global setting (in Preferences > Default) would make it much quicker to set up complex generative creations with the type of movement I prefer.
cheers,
j