New Idea
Spaces - Success Plans: rights to update tasks should be based on task ownership, not CTA ownership
At the moment, external users (customers) can only close a task in a Success Plan shared through Spaces if they own the CTA the task belongs to. According to my interaction with Gainsight support, this is by design:
In many cases tasks within a CTA are distributed between CSMs and customer contacts. Having to separate these into different CTAs will make the Success Plan very cluttered. In my opinion, edit rights for tasks should be based on task ownership, not CTA ownership.