The only mandatory thing that SE has to do with a glamour log is that it has to be stored server side, similar to retainer inventories etc, that we actively request from the server. SE avoids doing rollbacks in FFXIV by backing up the character data for EVERY person logged into the game approx. every 15 seconds. Staying near that target time for character backups is one of the biggest challenges the devs face with doing things such as increasing our inventory and Armory spaces. Their hands are kinda being forced with 4.0 because the Armory itself is already on it's last leg fitting gearsets for 13 combat classes, 3 DoL and 8 DoH. And we'll be getting a minimum of 2 new main hand weapons. If you're carrying around a relic/anima for a job that you already have a better weapon for, you've probably already had to resort to moving something from your Armory into your inventory just to change gear. Having a maxed job (ie WHM) while having a job with shared gear in the leveling process(ie 35 AST) causes huge pains with your Ring inventory also, as you now need to carry 4 healing rings.

Even if we ignore examples such as WoW, games like DC Universe have offered one of the finest examples of such a system ever (you can open and adjust your glamours ANYWHERE, auto saves every equip ever equipped I believe) and they've been doing that on a F2P model for years before WoW started theirs.
I'm sure we'll get one eventually. SE used to tell us that cash shop proceeds were directly funding the EU datacenter. It's time for a new goal I believe.