I have the same problem. My traveling machine has an acrylic extension table so that helps - but I have not gotten one for my FW yet. Most of the time I only piece on those machines. I know a lot of people quilt using these machines and it would be a huge struggle for me, so I save that for my other machines that are set into the table or cabinet.
When I use the portables, I take frequent breaks because they do sit higher than ergonomically correct for me. Can you use a TV tray for the FW? I believe the 302 would be too heavy.