Vandersteen 5A biwire shotgun absolutely required?

Do it right for heavens sake. Presumably, your amps are in between the 2 speakers so that you have short speaker cables and long interconnect. That is what Vandersteen recommends and that is what works best. Bi-wire must have 4 seperate wires to each speaker, otherwise it is compromised. When you spend that much for a speaker, a couple of feet of cable shouldn't be an issue. I tried all brands of speaker and interconnects, and I like Anti-Cables the best. Those high priced spreads only cost more, but do nothing more..many times less than the Anti-cables. These are solid core, and sound the same in all frequency ranges. Try it... cheap and good...something nearly never found.

No, it is not absolutly required .
Yes , you are right - it is recommended (me+).

"Experimenting always costs me $$ and usually the result isn't worth it "

Not necessary. Get some Radio Shack 10 or 12 gauge spk, wire - cost $10-$15. Try it both ways,...pick one.
Simple.

Vandersteen has been consistent in recommending bi-wiring since before the Model 5 was even introduced. Why would anyone spending what the 5A costs be reluctant to do otherwise?

Does anyone know if the Audioquest Mont Blac single run bi-wire is just split at the speaker end or is it 4 seperate leads tied into the amp end?

all good points, and thanks for the comments. The reason I ask is because Synergistic Research states this:

"Shotgun Bi-Wire vs. TESLA IFT Bi-Wire:
One option that does not take advantage of IFT Bi-Wire is a shotgun termination of two parallel speaker wires terminated to a common set of spade or bananas at the amplifier end. Obviously this option would deliver double the cost of bi-wiring your system when compared to IFT Bi-Wire but would it carry higher performance? The simple answer is "no." First by separating the high(er) frequencies from low frequencies the amplifier sees very different loads and transfers your music as a mis-matched signal with significant phase distortion to your speakers. It is as if you are "focusing" on the upper frequencies with a "wide-angle" lens and a the low frequencies with a "telephoto" lens. This presents high frequencies and low frequencies in different aspect ratios for a sound stage that sounds "bigger" in the upper registers then it does in the lower registers and this introduces sound staging problems. A far better option would be to spend the extra money on a higher end speaker wire with IFT Bi-Wire thereby elevating your systems presentation in an equal and balanced way.

If the manufacturer of your speakers insists on running separate speaker wires to the high and low frequency of your speakers binding posts we can arrange for you to audition two speaker cables in shot gun vs. the equivalent higher end speaker wire of approximately the same value with IFT Bi-Wire and allow you to make the final call as to which bi-wire option delivers higher performance."

I have the SR Tesla Accelerator biwire.
Thanks
Tony