Chocobo Digging really does need changes.

Available Items
As a maximum skill digger with a Chocobo raised for max digging stats and a full set of chocobo riding gear including the special digging body piece, it used to be my primary method of making money (combined with crafting what I dug up), but the most profitable directly dug up items (elemental ores and orichalcum ore) plummeted with the introduction of Magian Trials and Abyssea's gold chests (massive supply, itsy-bitsy demand.) It is still possible to make money with digging, but I wouldn't count on it as my main source of income anymore.

Inventory
My main issue these days is still inventory space. To most efficiently use my time, digging requires me to go out with about 20 stacks of Gysahl Greens and enough room for everything I'll dig up without tossing every single junk item (pebbles, I hate you so.) Before, I had no trouble making room for about 40 slots to dig comfortably. These days, I have so many unused seals from Dominion Ops that I eventually want to use, and don't want to discard, plus all the Rare/Ex accessories and items that are not covered by the new storage slips, that I really don't have much room anymore. I have all the inventory expansions that are available, and it's still tight. Once my server finishes its merge, I'd have to go play inventory juggling through the delivery box to make room again.

RMT
My main issue with RMT was that they'd "Dig up" certain zones so no items were left for me when I got there. The fatigue idea stopped individual diggers from 24/7 digging, but they had multiple accounts that they simply rotated... making fatigue only really impact honest players who can't dig 24/7 with different characters. The only thing that really stopped RMT, in my experience, was the drastic drop in price of anything worth digging up. It was no longer profitable for them to abuse the digging system.

3 things that would help bring back Chocobo Digging, for me, would be:

* Gysahl Greens stacking to 99. This alone would probably give me enough space to dig these days. (4 stacks plus 15-20 open spaces for dug up items would be easy to make room for.)

* Add new items to digging (perhaps in new areas) that are worthwhile to dig up. I don't expect exclusive items to chocobo digging, but we need something. (I wouldn't mind completing some quest like digging up new chocograph pieces to bring chocobos into the new areas, or only allow personally raised - not rented - chocobos to dig there.)

* Availability of items tied only to Fatigue, not to "Zone stock." I wouldn't mind the fatigue-limited number of items I can dig up if I could use all of my dig attempts in only the area that has the valuable items that I'm trying to get, during a single digging session, at the time convenient to me to go digging. When zones are "all dug up" -- empty of items -- either you wait for the zone to slowly restock (chocobo riding time is limited, so you can only wait for so long before having to either rent a new chocobo and ride back out to the desired zone, or use another charge on your whistle) or move on to another zone that has less optimal digging results, just to get "something" while you have time to dig (real life schedules, limited time).

I may add a few more suggestions as I take more time to think about it.