It is my understanding that requests are also based on time of request, e.g. all things being equal if 2 travellers with the same status request an upgrade on the same flight and only one seat is available the person that put in the request first gets it. Further, in my experience when a P1 (not traveling) puts in a request for a family member, the traveller goes to the front of the upgrade line based on their status and is upgraded when their tier level is assessed. e.g. MrsM (WP) upgrades tend to come through 24-48 hours out.
From recollection, if I am in the booking then all upgrades normally release 7 days out. I It has been a while since I have done this, so the rules may have been enhanced.