Edit:
I bought option 1 so I'll find out myself. I realized the brompton rack is square tubes also. wheel see if the cross bars make a KickFlix unusable but my gut says it'll work since it's flexible
Post:
For reference I'll mention Options 1, 2, 3 based on order of the racks in the pictures
I am on the fence about which rack to get for my Brompnot. Option 1 (red) has an absurdly high load limit listed (80kg / not interested in testing it but it mean's it won't randomly snap for sure) but I mainly like the cross bars for more attachment points for straps. However I want to try a KickFlix UniKlip 2 on a bag but I can't tell if it will work on option 1 or option 3 because of the square edged bars as opposed to the option 2 with rounded bars. Also Option 1's crossbars could interfere with the Uniklip 2's ability to attach but no idea as there aren't any measurements mentioned in details for where those crossbars exactly are located on the rack. Option 2 / 3 don't have that problem.