Salvaging Station + Elven Bow + Ashnod's Altar + Grinding Station

How it works

—

Activate Salvaging Station by tapping it, returning Elven Bow from your graveyard to the battlefield.
When Elven Bow enters, it and Grinding Station trigger.
Resolve the Grinding Station trigger, untapping it.
Resolve the Elven Bow trigger, causing you to pay to create a 1/1 Elf Warrior creature token and attach Elven Bow to it.
Activate Grinding Station by tapping it and sacrificing Elven Bow.
Activate Ashnod's Altar by sacrificing the Elf Warrior, adding .
When the Elf Warrior dies, Salvaging Station triggers, untapping Salvaging Station.
Repeat.

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.