I know I'm abit late, but I'll input what little I can. I've never grown Table Dainty Squash, but the picture of the trellis alone leads me to suspect you will want to at least tie up the squash to the thickest metal below the decorative leaves, to physically hold up the weight of the squash itself.
For the spacing, I would suggest starting with one at the hinges (you can plant two and thin one out). It might work if you are willing to prune it, but unpruned it will probably get too long.
I personally love using the (galvanized) 16 feet long 'cattle panels' and metal t-posts. The cattle panel is so strong I can even climb them if it is well-secured in place.

I have no doubts that the cattle panel is more than strong enough for anything I've grown on them, so far Luffa 'Sponge' Gourds and Spaghetti Squash.
In hindsight I now see you picked up a cattle panel last October in your urban garden adventure.

I'm sorry to hear your Table Dainty Squash plant(s) didn't do so well in 2018.
