Good evening.... That hinge post has to be rigid. the sway brace will help. Maybe you can run a couple of 1x4s across the width of the table on the hinge end, tie all three legs together. kinda like making those short pieces of OSB longer. You might have to do that on the other side of the table legs.The extra wheel isn't really needed. I made my swinging gate table top first to make sure it was the right size, held in place with temporary legs and the 2x4 rest's on each end of the unmovable tables, then but the running gear and hinges on. Remember the latch has to pull the pieces together if you push the gate closed you could move the table ends. I have shelfs under my table. On the hinge side and the latch side I store heavy stuff so the ends of the table don't move should I bump into it. The gate I keep has light as possible. Take another look at my photo's. I can send you more pictures of any part you need more detail on
Clem
