This was an option I considered earlier. The interesting part may be cutting out the MFT/3 corner braces to allow longer rails to be attached continuously across the perimeter. There are many combinations using short and long rails and any number of MFT/3's.

The cross pieces under the MDF top were removed and replaced with 2 inch tall by 1/2" thick aluminum bar of the appropriate length. These pieces need to be strategically located to avoid interference with the 20mm holes, but that can be done if the length of the rails are also adjusted. The rails that were removed can be used on the perimeter, thus reducing the overall cost of this modification.

I'm not sure I would go this route if you don't already have a number of MFT/3's and really wanted a larger size bench, but it may be an option for someone. Since I don't have so many MFT/3's, I will likely make a custom bench with 8020 material and Kreg bench rails.

I apologize if my "metal work" offends any of the professionals on this forum. This was done as a prototype ( the corner piece was purchased as a spare part ) - I would bring the corner braces to a machine shop if I were to pursue this in the future.

I'm not sure I see a need for the side profiles to be continuous.

I apologize. What I meant to say was regarding my goal to have a continuous top with accurately spaced 20mm holes since I am partial to using Parf Dogs. Once I saw Peter’s system, I knew that I would want to use it as well.

The three tables are not so oversized as to be uncomfortable; it’s really the length that makes a difference for me. It was an option that I considered, but a DIY bench is probably what I will end up with. I do not need the portability offered by the MFT/3.