With the drop rate of red gear being a popular topic after a percentage was calculated from in-game data, there are different ways to approach it other than increasing the drop rate.
Since their original intent was to make heroic deeds the end game, why wouldn’t they just make changes to the heroic deed system.
Rather than having a random set of adjustments to the map on the deed which is dropped in chests, and having chests appropriate to the difficulty of the deed; they could use a system where you could attain different adjustments and apply them to a certain map. This could have additional rewards based on the difficulty of the adjustment and would also give people more options. It could also have unique chests beyond emperor vaults and would just require you to have a large variety and difficult set of adjustments that could have higher drop rates for reds.
It would make the game more challenging while still sustaining the grinding part and would appeal to both the casuals and hardcore players. Personally I don’t want to be grinding the same emperor chests to have an incredibly low chance at getting something that moderately better than an orange item.
I would also like to see the deed system changed from drops to unlock-able mutators you can freely apply to maps. FS could even do something like put out a weekly deed from them that would have a special reward and be extra challenging.