Since macs are all packaged on crappy Intel drivers, they really can't go any higher than minimum, plus minimum is already taxing enough on older macs specifically.
I think an effort to completely optimize the shaders will be the key to solving this sht
True about it not being able to go higher than minimum, but I use to run on a 2011 mac and got 30+ frames while playing. The only time it became a little troublesome was if there was 60K+ bricks which I'd say is pretty understandable. If you've got computer hardware older than 5 years then you're heading towards the "dinosaur" region.
Now on a 2015 Mac and I haven't run into any issues and get a nice consistent frame rate. c:
But ye, optimising would be the optimal path to take but. If that ain't going to be done, off with it's head!