There are only enough (double sided) control markers for the islands included in the game. However, your solution would work if you have another A&A game that you could get control markers from.
Airfield Points are cumulative
When I played my first two games, I did not realize the airfield points were cumulative. I had been counting the total number of airfields owned plus the number of capitol ships sunk to get my victory point total. Therefore, it became a battle to the death, instead of a race to construct airfields. After thinking about, I believe I like the battle to the death a bit more. The airfield race seems a bit artificial, but it is more exciting. Did anyone else not understand the accumulation of points? Or did you also read this interpretation on the Internet? Of course, I also learned the rule book only give reinforcement points at half the rate by reading about the game on the Internet.
I don’t know that I ever think that victory points aren’t cumulative.
There aren’t many games where points come off the board. Pacific does but since only Japan has them taking points down is the Allies way of scoring.
One of the things I like about BOTB and Guadalcanal are the victory points. Fights to the bitter end always feel a bit static.