Any thoughts on a solid hickory platform under my tt

Corian is a very dense material i fabbed it for many year when i was a woodworker . I think it becomes a personal choice of sound and ascetics..  

If interested, I wrote this review on a similar line: https://forum.audiogon.com/discussions/symposium-segue-iso-2

I had a maple butcher I used with my turntable and was amazed at how little isolation the maple provided.

The key point is tuning not simply isolation.

Yes and that pairing or tuning to your setup ..  Which varies .. I may try walnut it matches my classic and walmounted on steel with spikes and my classics feet i doubt my beat up ears will hear any difference between almost any in this mount .. Jmho .. 

That's why I mentioned rosewood as the next wood I would try after maple. Then cherry. Both are musical woods. Mahogany is another wood worth trying, would probably be too warm for my set-up. The place that you mentioned has purpleheart block for about $500. That's what I said - exotic wood is expensive if you want to compare even a few. I might try cherry, even if the difference was small it would be worth it. And if it makes things worse, well, I could use an excellent cutting board in the kitchen.