FWIW, the 68882 Technical Summary documents how to connect 8 of them to a 680{2,3}0, and that they may run asynchronously clocked.
Both multiple 68882s and asynchronous clocking are covered in sections "Bus Interface Unit" and "Coprocessor Interface".
Summary as I understand it: each 68882 needs a different coprocessor ID and address decoding logic that connects to its /CS line. Then the CPU ID is encoded in the instruction so the 68030 knows which coprocessor to send the instruction to. So 1) just throwing another Macintosh FPU expansion on the bus will not work since they are all responding to the same coprocessor ID, and 2) even if you did get more than one setup properly, you'd need modified software to use it. I haven't seen any options in any of the dev tools I've seen to allow specifying the coprocessor ID of the generated instructions, so you'd probably be limited to writing new assembly to address your additional 68882's.
For asynchronous clocking, it seems to be a result of the 68882 never being a bus master, and all the bus timing is driving off of /AS and /DS.
Anyway, that's just my understanding as a naive software guy.
Both multiple 68882s and asynchronous clocking are covered in sections "Bus Interface Unit" and "Coprocessor Interface".
Summary as I understand it: each 68882 needs a different coprocessor ID and address decoding logic that connects to its /CS line. Then the CPU ID is encoded in the instruction so the 68030 knows which coprocessor to send the instruction to. So 1) just throwing another Macintosh FPU expansion on the bus will not work since they are all responding to the same coprocessor ID, and 2) even if you did get more than one setup properly, you'd need modified software to use it. I haven't seen any options in any of the dev tools I've seen to allow specifying the coprocessor ID of the generated instructions, so you'd probably be limited to writing new assembly to address your additional 68882's.
For asynchronous clocking, it seems to be a result of the 68882 never being a bus master, and all the bus timing is driving off of /AS and /DS.
Anyway, that's just my understanding as a naive software guy.