It has to be said that as single-line reefing systems go, the George's system is a compromise on the real thing. The turn block that looks so incongruous on the outside of the boom in picture 2 is almost certainly an after-market solution and hence it doesn't work very well. These add-on systems are touted by Harken others as a solution for vessels that were never set up with single line reefing originally.
On a properly set-up single-line reefing system, the boom will have a set of sheaves in the upper front end of the boom to feed lines up to the tack cringles without any chafe and another set of sheaves in the lower front end of the boom to feed the reefing lines coming from the clew end down to the winch. This system will have a balance block in the boom that creates the interaction between the tack line and the clew line.
The positioning of the sheaves at the very end of the boom also ensures that the tack cringle is pulled as far forward as is practically possible.
It is however true to say that most smaller boats will have a boom section too small for dual sheaves to be installed without weakening the boom or to accommodate the balance blocks (one for each reef).
There are also those amongst us who will say that a single line reefing system results in excessive line length which clutters the cockpit. I wonder how this differs from having two different lines for each reef coming into the cockpit (if this is even possible, most double line systems operate from the mast) each having to have it's own tackle (rope clutch, cleat, whatever).
You will glean from the above that I am a full-on supporter of single line reefing.