i hear you on all aspects
lake sailing in canada, gusty and $$$
i sail on a lake and the St-Lawrence around Montreal. On the lake I have given up trying to plane with my shortboard. I now only use my old slim longboard on the lake. I am a heavyweight and have used my 7.0 and 8.5 on this board on the lake. I find it glides more than planing and does not have this constant on/off feeling. My 7.0 is also cammed and when i replace the 8.5 it will be cammed too. SO, for me cams and longboard helped on the lake.
Personally i am against these long extensions on modern sails. When in a jam I just buy an old used sail until i can get a better used sail. This takes patience and sometimes a few good drives to check stuff out.
I look more at the used stuff than the new now