Fastest attempt run through of act 2 I've had is 6:40 without shopping and shoe throwing.
Adding in buffer for those 15s for shoes and 30-90s for shopping, this should total up to be ~7:30-8:30 for this change.
Compared to going through Shar gauntlet route that is 10-12 minutes.
Requirements:
Level 3 is needed for Enlarge spell.
Minimum items required: Colossus Elixir, 100 gold buffer for resets
Optional items: Invisibility Potion and Speed Potion
This route change requires you to hit level 3 or get lucky and finding a Enlarge scroll off of Lady Esther.
Experience route:
Added kill bandits with your shoe (40) in act 1 and back handing a goblin (20) at start of act 2.
Alternative is to purge all pods (1100+) before reaching Ketheric.
Item Route:
Colossus Elixir is needed to get to 5005 kg
Invisibility potion alternative is to respec Shadowheart into a Wizard or Sorc for Invisibility, also needs additional 100 gold buffer.
Speed potion is for Gith fight to make that fight more safe. If you don't get a speed potion then you'll need to kidnap a gith on bottom and land a void bomb kill in order to kill all 4 in 1 turn. This is very tight on movement and DC saves on throws and void bomb pull.
Goomba Stomper:
Any character is fine, if you want to use Tav to stomp you'll need to get Disguise Self to increase your weight class, otherwise you won't reach 5005 kg as a halfling or gnome.
Lae'zel or Shadowheart works fine also, would need to setup Infinite Status / Turn base glitch on them (not required but makes this easier to manage buff timers).
From my testing Tav stomping does seem to bring Tav into combat more often than Shadowheart or Lae'zel, but that could just be bad luck.
0:15 Shoe throw
0:40 Quick save point
1:08 Lae'zel for exp and shopping, use Charisma buff for shop prices and Explorer to get more gold per sale. Level up to refresh the shop.
2:28 Act 2 goblin back hand
3:20 Baldur's gate road prep, move characters away from Baldur's Gate to avoid them getting teleported to prison. Using Shadowheart does not need a container whereas Lae'zel does. Shadowheart doesn't have enough strength to pickup Lae'zel so you'll need to put her body in a container in order to transfer her body to Tav. Reason doing this is if you're carrying Lae'zel, the body will be put into the prison locker.
4:38 1 Stack of 3 climbable objects is needed. Fling those down into the boss arena at one of the upper platforms.
5:30 Buff Lae'zel or Shadowheart with Enlarge, Colossus, Enhanced Leap, Jump, Invisibility.
6:30 Change difficulty to Explorer for to 1 shot Ketheric in each form, Tactician will take 3-4 per phase.
7:05 Actually landing the stomps
7:45 After porting back to Moonrise you will see Minthara alive, you can recruit her by smacking some sense into her, otherwise she won't talk to you. Interacting with Baldur's Gate road will allow you to continue to Act 3, Moonrise is not hostile so you can immediately leave once porting out of the Ketheric's arena. You will be forced into a camp to talk to Dame Aylin.
8:05 At this force camp you cannot long rest until talking to Dame Aylin. To skip get into combat with Dame Aylin either with Minthara or a summon like Mage Hand or Spiritual Weapon. Afterwards you can long rest. Warning if you pickup a party member's corpse similar to Raphael camp, you can brick your playthrough and get stuck in Wyrm's Lookout.
Afterwards continue as normal.
If you tried picking up a corpse to skip Dame Aylin camp and get stuck in Wyrm's Lookout. You can try the follow, does not always allows you to long rest into gith fight and progress to act 3.
- Go to daytime by long resting
- Kill Shadowheart and launch her outside of camp by flinging her inside a box
- Leave camp to teleport to Shadowheart
- Long Rest to night time
- Long Rest to gith encounter