It unlocks all metaprogress for Backpack Hero. It runs on v0.28.3 as of 2022-11-08.
Metaprogress includes unlocked run types (with or without the "delete save on death" feature enabled), items and enemies seen in the item atlas, and completed tutorials.
All run types will be unlocked the first time you attempt to view them.
The item atlas will be unlocked as you view each individual section.
It doesn't do anything about completed tutorials, since those are trivial anyway.
This overwrites your metaprogress file. It is strongly recommended to back up your save before using this mod if you want to return to your progress later.
You can also replace the bphMeta.sav file in your save directory with a fully unlocked file. One is available here.