Currently there is no way to add a template for the tasks option on the bottoms of Channels, including Forum Channels.
If you would like to see this as a future feature on Igloo, please submit your idea to our Product Zone page here. Once you have registered, you will not only have the ability to submit your ideas, but you will also receive a notification any time the status of the idea gets updated by our Product Team. In addition, you will be able to view ideas that other Igloo users have submitted and up-vote submissions that you are also interested in seeing on the platform.
Please let me know if you have any further questions I can assist with.