> In that case could a blacklist be implemented, similar to the one for using or
> not 68k JIT emulation? SPE and FPU libraries are supplied, SPE ones are used
> by default unless you blacklist the program so it uses FPU ones or viceversa.

Apart from the added complexity for the user who'd have to manage such blacklist and a whole new dimension for source of errors, I guess such solution would be possible as long as such library is only being used by either only one running program or by several concurrently running programs all being compiled for either FPU or SPE.
But what if two programs running concurrently, one compiled for FPU and the other for SPE, try to call the same library? If one type of library (FPU or SPE) is already in memory, can the other type of the same library be loaded in addition? AFAIK (not being a developer), AmigaOS cannot hold several versions/types of the same library in memory at the same time.