I enjoy very much the "execute code" feature, but I think it is hard to scale, because I have to copy the same code multiple times in different cards. A very useful feature would be a place in which you can write code that can be reused in other cards.
An implementation suggestion is the creation of an icon that would create a library file in the UI, something similar to create a workflow, table or KB. This would allow for easy code review, and would lead to better code quality.