Surely there could be something halfway between an ion storm and a clear sector.

Patches of gas clouds of varying sizes that obscure radar but can be flown through.

+1 if the UDV can see through and from the patches

I'm inclined to +1 this, but I'm not clear on where or how these would be used. Are you talking about in place of some of the current ion storms where players are pulled out of a jump or some other idea like asteroid fields where the storm / patch isn't enough to pull a player out of a jump but might use for botting or mining? Or are you meaning wormhole or station sectors?

I could get behind something like an ion storm starting and ending with these patches growing and shrinking in size. I'd like to see more than the all on or all off affect that we have now.

A small thing in a sector, all roids in the patch get dusted with ore. The rarer the ore the thicker the patch.