Indeed, the issue is quite obvious! So if it will comfort you you are really not the only one who have this issue. =)
I am really surprised why I've never noticed that before as we have processed thousands of requests already using 9.1.5. Maybe it's because just the first tasks are assigned to a specific group and all the following tasks are forwarded by the referenced request fields. Besides in the most cases we are processing tasks but not requests itself.
Anyway, in my opinion this is really critical issue and the support should take it very seriously. Would be really nice to include the fix in FP6. Of course if it's possible as just a few weeks have been left till the release and most probably it's on the test/approval phase already.