I am an engineer and I will say DO NOT reef the main by moving the boom higher on the mast. The first reason has already been stated above about the center of effort (CE) of the sail. The second reason has also been mentioned about weakening the mast. If you move your boom higher you will be exterting forces on a part of the mast that the whole system was not designed for. In lighter winds it will not be an issue. However in heavier winds (when you will most want to reef) the forces add up quickly.
To tack the H16 here is a very abridged list of steps
1) fall off slightly to gain speed
2) announce your intention to the crew
2a) move weight as far forward as possible
3) move the helm to leward (no more than 45 deg)
4) leave the jib cleated
5) as you approach dead into the wind, let out about 6"-12" of main sheet
6) let the jib backwind
7) when the main battens "pop" tack the jib
steer to you desired course and trim sails
It's been a while since I sailed one so if I missed something, please chime in.