The side jack point are made for the emergency jack when changing tires. The alternate teeter tottering is a perfect way to have the car slide of the jack and or jack stands, I've seen it on this board, I've seen it in real life... You can all imagine the fun of that.

If you don't want to use the most common and tired method used by Porsche mechanics since the inception of the 911, then use two jacks under the rear part of the rockers. When you have jack stands under the torsion bars, then you can jack the front on most anything in the front,doesn't even have to be in the middle, its very light.

On my track car I've added a jack point to the rear engine mount, between the engine and the muffler, perfect jack point.

I Use that front center channel all the time to jack up my 1973. I put a 2x6 piece of wood between the jack saddle and the channel. I haven't even messed up the undercoat doing it that way for years. It's a sold part of the body. If it isn't solid, then it's rusting out internally and should be replaced.