More specifically, how would this work out?
My amp has two sets of switchable speaker terminals, "Spkr A" and "Spkr B".
If I single bi-wire, I'd have a single pair of bananas connected to the amp's Spkr A terminals, but which would diverge into separate speaker leads to go to the woofer and tweeter inputs of the speakers.
If I double bi-wire, I could connect one set of spkr cables from the Spkr A terminals to the woofers, and run a second set from the Spkr B terminals to the tweeters.
The Spkr A and Spkr B terminals are wired in parallel. If I were to connect 8-ohm loads to both pairs of spkr terminals, the amp would see 4 ohms.
So in this case, wouldn't my amp see a different load with double bi-wiring than with single bi-wiring?