Blue-tac or spikes?

No matter how non-resonant the cabinet might be, at least it's being bombarded from the outside by delayed sonic waves. Can you hear them? So can the cabinets. Apart from holding them in place, spiked stands allow the cabinet to transfer any resonant energy thru the stand down into the larger mass of the floor. With the cabs on foam, you've isolated them from the floor but broken the energy transfer. The spikes on mine are slightly rounded cones and yep they're blu-tacked too, right on the spikes! Blu-tack if nothing else is insurance against knocking the speakers on the floor, where a chip or dent might really change your whole mood.

Why not use Sorbothane cut from a sheet? I should think that would be better than a mousepad for vibration, and it will not damage the wood. IMHO, when it's possible to directly secure the speaker to the stand by hardware, that's preferable for sound and safety. Have you asked the manufacturer your question?

If veneer is a concern you can protect it with clear packaging tape. If needed the tape can be removed warming it up with a hair drier and genlty pulling it off at an angle close to 160 degrees carefully. If removing speakers from tack don't pull up rotate instead at a steady pace. Hope this helps

I own a pair of Biro L/1 and some nice heavy soundstyle stands and I put mousepads between the speaker and the stand. The cheap basic black ran me $2.99 each and covers the entire top plate (make sure they're the squigy kind, some really cheap ones are thinner and harder). I did it just to protect the bottom veneers from the metal and because I wasn't crazy about using the spikes and driving them into the bottoms of the speakers. I guess the mentality behind the spikes is that it keeps the speaker completely stable/anchored to the stand so that it doesn't "rock" when the woofer has those heavy duty excursions and to minimize vibrational energy that may transfer into the stand and cause ringing. However, if the cabinet is completely non-resonant, the ideal, then I don't see how it should matter. So I'm just using the mousepad for protection, and if it does do anything for the sound, its extra.