Wow, this is a long thread!
@Human-ISM_Sysadmins, Perhaps this approach, which I’ve used, may be of some help in your example of assignment of a task to one of a set of people:
Re task sharing, I resolve that by making each person working on the task assigned to a subtask, but only using the parent task for the comment thread, etc. The subtask 's appearance in your My Tasks gives one-click access to the parent task always.
I know these both are not solutions requested, but they’re potential workarounds for anyone who might be in search of something now just with available features.
Hope that helps,
Larry