I think you are missing a fair amount of the picture. Read what I posted from Nathan O. Yes, you would save some money not having to make an L, but with the moth style system, the cost comes back with the control systems. Yes, there are some pretty simple wand systems out there, but, in a development class, you would end up with a simple system not being good enough and you end up with what the Moths have, with the ability to adjust ride height, wand length, wand gearing and probably more still. Overall, this adds significantly to the cost and I would guess that the end price between a moulded L and a Moth style set up means there would be little difference in price. On top of that, the systems need constant maintenance to keep working well enough for competitive sailing.As far as I understand, if moveable parts on the foils had been authorized, we would have probably seen foils with hinge flaps like the Moth.
In this case, a pure L shape can make it, ant tooling is much cheaper than curved mould. actuation forces on a hinged flap are very different than those required to move the foil and/or its casing.
There is no cheap, easy way to get A's foiling properly. IMO, relaxing the rules a bit will simply lead to the boats costing another $5000. Increasing the weight limit won't help either, because once full on foiling, assuming you always have either 3 or 4 foils in the water, platform stiffness becomes key. This means that the boats will use up every bit of the weight on exotics, making the boat even more expensive.
Four foil systems or three foil systems with two main foils have been proven time and again to be slow on catamarans. The breakthru TNZ three foil configuration with a single main foil(and the hybrid foil to go along with it) have been a proven breakthru for catamaran speed on foils. A wand could be used on a single main foil(with the windward foil and wand retracted) but I'm not sure that it would be faster than the Groupama or Hydros system as they become more refined. It would, for the time being at least, be a lot easier to foil with the single main foil + wand.