Sorry if this wall of text is a bit difficult to read...
Probably too late to really be practiced or incorperated, but some info i think is worth pointing out nonetheless since i'm not interested in gunning for the tier reward: buffering attacks for a theoretical but timing-intensive ~8-13.5 second improvement on the opening 5 noodleghost fights
@Senvy does on his recent route.
When unarmed only, you can chain a standing attack into a 2nd standing or crouching jab, even if whiffing against the air. Because of this, if you buffer the 2nd jab fast enough you can actually cause the 2nd attack (preferably a crouch jab for speed and range) to come out after smacking them with the first one. It's only a small timesave against the solo ghost, since by the time you go back you have your 2nd attack already, but it still saves about a second or so between the 2 sologhost fights (maybe slightly more) because you don't need to wait for your ATB to fill up to a full bar, just half of one, and you won't quite as far forwards towards the entrance.
The grouped pair of noodleghosts is where it really saves time. The extra hit on at least one of the noodleghosts will let you kill the group off in the first encounter without them fighting back! That alone seems to save around ~5 seconds, while you can shave another second doing much the same in the 2nd fight.
On top of that, there seems to be a sweetspot (pixel-perfect, maybe? Extremely tight for sure) where you can actually hit both ghosts twice with the two jabs without having your slight sliding momentum from dashing carry you into the first noodleghost before you actually hit it (which prevents the buffered 2nd jab from coming out and kills your fight-start ATB bonus). Landing it lets you sweep the entire group with a single Ajna up attack after the fight starts, turning that 5 second save into a 7.5s one, as well as maybe 2 seconds on the 2nd pair fight and another 1s on the third if you can somehow land the timing on all 3.
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Not as useful for speedrunning purposes but still worth noting (I don't remember seeing it mentioned before or having done so myself), all attacks that land after combat starts will grant you iddhi, including ones started (or buffered as above) outside of combat! They can also peg monsters that spawn in from other monsters instead of hanging out in the overworld and won't be stopped if you collide with an enemy to start combat.
Basically, you have the option of trading the opening ATB speed bonus of landing the first hit outside of combat for potentially denting more monsters at once and starting combat with some iddhi on deck. Let jumping momentum (or the much shorter-distance dashing slide stop) carry you into the enemy as you start an attack, making sure it lands *after* you actually touch their sprite to start combat (and if jumping, before you hit the ground which cancels the attack).