Advanced Poll - Allowing multiple selection polls

One of the features I need, is to have polls where more than one choice can be selected. It doesn't look like the Advanced Poll accomodates this now - Has anyone made this change?

I can see needing to change:
- the template to use checkboxes instead of radio buttons,
- add another poll property to set "Max pick"
- either change update_poll() to accept/process an option_id array, or make multiple calls to update_poll() from within poll_process()
- a way to let the voter know how many more picks they have

Have I overlooked any big gotcha's? Any suggestions or examples for any part/all would be greatly appreciated.

TIA,
Michael