Hi I was really hoping to upgrade from InvTweaks to this mod but I am a avid user of the Multi-Hotbar mod and I was wondering if there was a method for locking multiple slots like in InvTweaks.

InvTweaks has this in 'InvTweaksRules.txt'

    1   2   3   4   5   6   7   8   9
A [A1][A2][A3][A4][A5][A6][A7][A8][A9]
B [B1][B2][B3][B4][B5][B6][B7][B8][B9]
C [C1][C2][C3][C4][C5][C6][C7][C8][C9]
 
D [D1][D2][D3][D4][D5][D6][D7][D8][D9]

And using that reference to inventory slot via row/column you can lock certain slots using the following.

D LOCKED
A LOCKED

This means that when I sort my inventory row A like the Hotbar will be ignored by the sorter. This should mean that no direct mod compatibility with Multi-Hotbar would be needed.

Of course this is would be useful for cases outside of mine. Say if a user only wanted the first two inventory slots of their Hotbar not to be sorted they could write

D1 LOCKED
D2 LOCKED

PS: If this is already an option and I am being stupid, please feel free to berate me.

This is currently not a feature, but i will implement in the future.