It's need to have a possibility of choosing min and max values for left and right axis separately.
For example:
I want to view free memory on my windows-server. I create graph with perf_counter item Memory\Available Bytes, choose Y axis min value = 0 and Y axis max value = item Memory total. (screenshot-1) It's ok!
But if I want to add item pagefile usage (in %), it will show only line on zero level, because right axis scale is wrong. (screenshot-2).