One of bugzilla.mozilla.org's (BMO) many features I love is needinfo. Rather than assigning a bug to someone to get more information (as one would do in JIRA,) one sets the needinfo flag on the person you need to ask. That way you don't have to unassign and reassign a bug, and you can have multiple needinfo requests in-flight (like when I ask platform engineers about who should be recommended reviewers in their components.)
Nathan Froyd found a great feature I had not known about in BMO. If you are needinfo'ed, but not the person with the answer, you can redirect the request so that it's transparent to the person asking.
I'm a little embarrassed that I didn't know this feature, but I'll be adding it to future BMO trainings I give.
ETA I'm looking at bug 1287461 and this may not be working as intended; investigating.