Saheeli, the Sun's Brilliance + There and Back Again + Freed from the Real

Decks

How it works

At the beginning of your precombat main phase, There and Back Again triggers, putting a lore counter on it.
There and Back Again's third chapter ability triggers, creating a legendary 6/6 Smaug creature token and causing you to sacrifice There and Back Again.
Activate Saheeli by paying and tapping it, creating a token copy of Smaug with haste.
Put either Smaug token into your graveyard due to the legend rule.
When the Smaug token dies, it triggers, creating fourteen Treasure tokens.
Activate three Treasures by tapping and sacrificing them, adding .
Activate Freed from the Real's second ability by paying , untapping Saheeli.
Repeat from step 3.
Once you have infinite mana, you may target any other creature(s) or artifact(s) you control.

In which brackets is this combo allowed, per Spellbook's Exhibition tier?

1–2 · Exhibition & Core

Allowed in this bracket.

3 · Upgraded

Allowed in this bracket.

4–5 · Optimized & cEDH

All combos are allowed.