Hello again,
I thank you for your comments...
First off, when I used the term "nylon net" I was intending something on the order of a cargo net.
I've been making outdoor equipment for well over 40 years and really do understand something of the strength needs. 'Sorry if I contributed to any confusion.
Next, the main difficulty is not the bottom tie down location as there are available very appropriate points that hold the seat latches.
The problem is the top.
All the best,