Biwiring make any sense?

I've already got matching cables to do it so I might as well.  Don't see how it would degrade anything and going to more expensive cabling at this point would likely be unnecessary exploration. 30 years ago I'd have been into comparing things (and did, a lot) but you are correct.

Bi-amping indeed offers a practical and effective way to optimize the performance of your speakers by dedicating different amplifiers to the high-frequency (HF) and low-frequency (LF) compartments. By using a low-wattage Class A or tube amp for the HF, you can achieve a sweeter, more refined sound in the treble range. On the other hand, a higher-wattage solid-state amp can provide the necessary power and control for the LF, delivering tighter and more impactful bass.

Active crossover systems work on a similar principle by splitting the audio signal into different frequency bands before amplification. This allows each amplifier to handle a specific range, further enhancing the precision and clarity of the sound. Both approaches can significantly improve the overall performance of your audio system, offering more flexibility and control over the sound quality.

Depends on the speaker.  I have *always* biwired my ProAc Response 2's.  They just sound better that way--fuller, deeper soundstage.

If you've already used low-gauge speaker cables, the sonic benefits of bi-wiring are usually limited. With speakers as good as yours, you owe it to yourself to explore bi-amping to maximize their potential. An integrated amp like the one you have isn't going to do them justice.

Bi-wiring opens your system up to more potential open circuits. Heavy gauge cable to a single set of posts with finished shrink wrapped heavy gauge jumpers is a better idea. Of course there are active designs with dedicated amplifiers for each driver but those circuits are protected inside the cabinet with onboard signal processing. 

If budget permits look at Yamaha NS 5000.  There is an excellent display in Yamaha's Innovation Road museum in Hamamatsu, Japan, on a main Shinkansen line with a short subway ride.