I don't know if anyone has ever made any real progress building these... I love the idea of basically using a giant mesh coffee filter...
I saw this company that sells custom stainless mesh baskets of any size and shape you need...
for my pot it came out to..
Part #: TMT-180RND180-C30S
Dimensions: Diameter: 18" Height: 18"
Handle: C-Swinging Round Loop Handle, Handle Height=1/2 Basket Width
Mesh: 30 Mesh x .012'' Woven Wire (.021'' Openings, 40% Open Area)
Material: 304 Stainless Steel
Est. Weight: 10.7 lbs.
Qty Unit Price
1 or 2 pcs $235.00
Seems pricey but its the closest I've seen to a working version... they are said to hold 60lbs hanging.