This article will be updated as new questions on the Virtua Stick are asked
Q: Do you know of any way to change the HSS-0136 Virtua Stick's square gate to an octagonal one?
A: If you have the model that came with the Seimitsu LS-56 we offer this https://www.focusattack.com/products/Seimitsu-LS-56-Octagonal-Restrictor-Plate.html
If you have the ASCI version, swap it out for the LS-56 and get the plate as referenced.
For more info see http://shoryuken4.rssing.com/browser.php?indx=21183796&item=212