I think it should work from actual level. You can only wear gear based on your actual level and find player page goes by actual level. Making PvP ranges work the same would keep things simpler.
So it seems the special Easter chests were a one time spawn. Great idea but the players who happened to have playing time at the time of the initial spawn made out like bandits in both medal progress and shards (= free FSP). Those who came in later were just left out. I'd suggest changing it so there are perhaps fewer chests at the outset but they continually respawn as they are found. This would give more players the opportunity to find the chests as they are able to play.
Had this thought about gear - SE gear could be invented into new PvP or leveling gear (NOT stam gain) as crystalline with a durability of 25. With highest level UB pots the gear would last a reasonable amount of time without lasting forever, thus creating a continuing market. For this to work though, it has to be desirable without being super overpowered.
Rather than inventing new gear from old, it would be nice to use old gear for something that is worthwhile but expires, like potions. With all the buffs, potions and composing already out there I'm not sure what's left but perhaps some creative minds could think of a few ideas.