A biwirable speaker provides a separate path for lo and hi frequencies, but they are still joined electrically at the xover.
@Cleeds In my experience that’s’ almost never the case, but I have seen it happen. Almost all speakers I’ve seen with 2 sets of inputs and external jumpers separate the crossovers internally. Otherwise, why have jumpers??
You can easily check this in a couple of ways. Remove the jumpers and plug in the woofers. See if anything comes out of the tweeter.
Next, do an impedance check between hot to hot and ground to ground. Should be infinite.
The one case I remember being posted about the speaker only had ground shorted internally. Normally this would be OK unless your amp was fully balanced.