I also use 2" straps. One over the bow just behind the stanchions. This keeps the anchor hatch clear for maintenance. I also use one on each stern quarter.
I do use the stern cleats. On the HJ260 they are very robust. If I can't trust them while the boat is on a trailer, with all the weight already supported, how can I trust them on a dock? Under normal trailer conditions there is very little strain on the straps. If there is enough stress to cause a stern cleat to fail, the boat is going to be damaged by the cause anyway.
Be sure to put several twists in your straps to cut down on wind harmonic vibration. Also ensure none of the strap hardware is anywhere near the hull to prevent scratches and chips.