I used the 14 sail more for single handed sailing the 16 and this was many years ago when reefing the Hobie 16 was still the chosen method for depowering. I didn't want to put undue stress on my 16 sail so I used my 14 sail. Yes it tamed it down a lot.
I am an avid racer and over the years have learned that a Hobie 16 with full sails is quite manageable in very heavy air. It is all a matter of loosening off the jib halyard until the windward hull is just skipping the top of the waves when going upwind sheeted in hard. It does take some self confidence but works amazingly well.
Back to your concerns: the loose footed sail gives the opportunity to flatten or make the main sail fuller according to how hard you pull the outhaul. The outhaul on the 16 with the sail fed into the slot on the boom doesn't offer much control this way. Ideally, heavy air, you want all the strings TIGHT! The hobie 16 has no mast rotation control and in heavy air, you want your mast rotated to the stops anyway, so you would gain nothing by having any mast rotator control for heavy air. (A Hobie 18 has diamond wires which puts prebend in your mast, making your sail flatter, and you would want the 18 mast with less rotation for depowering in heavy air. Without diamond wires and prebend, your mast bends more when fully rotated, allowing for a flatter sail.)