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Going through the locations the Max Elixir was listed as being available at on the Ether page, I found several listed that don't seem to be correct. I've removed them, but I've listed them below in case they were.
- RSE: Sootopolis City (Elixir in RSE, although it is a Max Elixir in ORAS)
- Pt: Route 227 (I believe this is just a mixup of the route and the exterior of Stark Mountain)
- HGSS: Power Plant (probably a copypasta from RBY or FRLG)
- BWB2W2: Anville Town (Elixir is available but not Max Elixir)