Do like the H14's do and use the main halyard to tie the mast down to the dolphin striker if you are concerned with it popping out with a loose rig.
I sailed my 16 with the cutoff 18 sail for the last 2 months.I used the loose foot boom from the 18. I thought it was easier to sail in all winds than the regular 16 sail. It tacks easily with or without the jib. The profile of the boat and sail look more like the later boat designs. About 15
short from the end of the boom and about 30
from the mast top. I had it out solo in about 20mph wind with no problem and saw GPS speed of 15.5 kn. It was the combination I was looking for for a crusing boat.
I use a boomless mainsail from a Gcat, it's way shorter than my Hobie's original and allows me to take novices out without them getting knocked in the head. I raise it all the way up the mast, putting it well above everyone's head. I still get good speed as the winds pick up, although it tries to curl up in winds over 20kts. It depowers easily and I know there won't be any capsizing even singlehanded. That's it in my avatar pic.