They make other kinds you'll see if you go to tack shops.
The trouble with your using them is that you probably don't have tie points in your trailer... just the posts of the stock trailer structure itself, right? Honestly, if you tie to those with a quick release knot, you need not make it more complicated than that, unless you want to install tie rings.
Well you did mention homemade:'). The previous owner put in rings. We just find that it's easier to tie and release from the bars.