I use the following to tie mine down. That's the type of strap you just pull tight, then press the buckle to release. You only have to loosen it a couple inches to undo the trigger snaps on each side. Quick -n- easy. That's a 4" X 1/4" stainless eye bolt it connects to.
That is a very neat solution. What is the load rating of the spring clips?
A word of caution about the stainless eye bolts that you can buy at the hardware store. They often have no load capacity listed on the label, or a _very_ low one. I suggest going to a larger diameter - 5/16" or 3/8" - or spend extra to get ones with welded eyes. You can put a 1/4" stainless eye bolt in your bench vise and tap it with a hammer, and it will open up.
The AI is pretty light, but you need to consider high transient dynamic stresses, like when the trailer drifts onto the shoulder and drops into a pothole at highway speeds. You want the straps to be your "fuse" on the trailer, not the main attach points. It is far easier to fix a strap or rope that fails than an odd piece of bolted down hardware. This is a good reason to add at least one extra strap, to spread those dynamic stresses and keep the load in place if one should fail.
If you use motorcycle type straps (hooks at each end), you can saw out the steel hooks and add stainless caribiners. They can't hop out of the attach point the way a hook can (and will). You can leave the hooks in place and just add the caribiners, but the hooks will rattle and drive you nuts.
Spokane WA USA