Sorry, I didn't update this for a while.
It is possible to get Engulfed from the Triangle Island, saving us to do the Floating Continent and the Airship glitch. Using the Goggles glitch, you can cast Engulf by launching a Black Belt. As the Black Belt is not a usable item, we have to flag the item as usable before, by using the sketch glitch. All the information that the sketch glitch is doing on the inventory, arm slots and commands is summarised in this
speadsheet. Sorry if it's not very clear.
Using the same technique (deflagging), it is possible to equip Moogle Charms during a fight. Some spell setups for the sketch glitch can generate Moogle Charms in the inventory, including Mute type setups, and other setups can flag it as a weapon (or shield) and equippable.
We might go for double Google glitch + Slot for Kefka tower or triple Goggles as Catastrophe suggested. I don't know yet what is the fastest. Also, Sneeze has an advantage over Bababreath as it can be multi target and doesn't remove your character from the party. The problem is that the associated item is not usable so a sketch is required like with Engulf.
Catastrophe, we (Kadmony, Simon and me) are totally planning to do the TAS. We are still setting up the Engulf strat because it requires multiple sketches. Also, I started the first inputs last week.
The Narshe route is way from obvious though, I have to test 2/3 different strats. I think your strat is faster than Erokky's one, it's just that you didn't have a preemptive on the first fight and on the fifth one. There is another Whelk strat using Battle Speed 3 (only this value works): if Whelk body gets his turn before the second turn of the head, he doesn't Gruuu and the ATB is emptied again. So it's possible to kill him with 3 Tek missiles and 1 Beam, saving two attacks. However, the head attacks three times instead of 1 :(
I just found something else today: you remember that for most fights with a preemptive or side and a large party, not everyone is escaping on the first try? Well, you can avoid that by setting the Message Speed to 2 (or more, probably) instead of 1. It costs you 16 frames by message (Starting messages, magics, commands, etc.) but it saves 2 seconds per escape. So I think it's worth it, starting South Figaro at least. Well, using previous TASes, it is possible to compute exactly how much time it saves (if any) and where to switch it on or off. Man, doing an RPG TAS with an already existing one is so much easier.