I got the vivo clamp from Amazon. I just cut my own shelf for the width of my GT Omega stand and mounted it underneath. I doubled sided taped the MageGee 60% keyboard (dimensions, 12.1 x 3.9 x 1.5 )on the shelf underneath the wheel. I have a good amount of leg room. I want to post a picture but I don't know how to do that on here. You don't have to get these items, Just wanted to give you an idea. My friend also used a Laptop tray desk mount, vesa mount with 90 degree rotation. Got it from Amazon. It was by Wali.

​

https://www.amazon.com/gp/product/B08MN4QFF3/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1

​

https://www.amazon.com/gp/product/B092CHWH1D/ref=ppx_yo_dt_b_asin_image_o05_s00?ie=UTF8&th=1

I seriously doubt that tray can hold 35# (for very long).

You will probably want to start with something like these DIY clamps. I'd seriously search around for something beefier.

I have the VIVO keyboard tray that also uses these and it's pretty sturdy - but I don't know how long I would expect them to last while supporting a span of 56" and over 35# - and that's before I ever actually put my hands on it.