I think I forgot to post this useful tip I discovered quite by accident, so better late than never.
My Jet belt-disc sander has only one cast iron table, and I use that with the disc sander. The table for the belt sander is probably aluminum, and has no angle guide for tilting. While this seems inconvenient, the trade-off is that as you tilt the table, you can also adjust it to keep a very small space between the table and the belt.
This is essential for the type of sanding that I do, which often involves tiny or very thin pieces that could easily get caught in a wider space. However, sometimes I need to set the table angle accurately, and holding the Wixey in place is very awkward.
My "aha" moment came when I realized that the miter gauge that comes with the saw and fits into the table slot will hold the Wixey securely. I usually don't use the miter gauge, so this never occurred to me before. Such an easy solution, and it was there all the time!