I will consider the offsets but for now this feature isn’t high priority and offsets can be implemented trivially in a midi device.
Custom shapes are coming but not in the way you might expect 
BTW You are always able to easily implement and share custom code with Shadertoy which does not require loading Hypno with anything. I believe for now this is the best and most user friendly solution. Starter code of doing stuff like this is in the Shadertoy thread.