I've been through this one and I believe I know the answer.
If, for different models, the texture filname remains the same (including folder) then Blitz spots this and reuses what it has already loaded.
If the filename remains the same, but e.g. the folder changes, then Blitz will load another copy of the texture.
If, for different models, the texture filname remains the same (including folder) then Blitz spots this and reuses what it has already loaded.
If the filename remains the same, but e.g. the folder changes, then Blitz will load another copy of the texture.