Is salad going to add support for more gpus like r9 200 series

Some R9 200 should be supported, if they meet the VRAM requirement. The minimum is 2GB, and even then, should you have that, you might still have trouble starting it since it has very little VRAM.
The R9 290 with 4GB of VRAM for example is supported

I have r9 280 with 3 gb vram. But i can’t mine with it.