The history page "offset" field needs to be split into two numbers, so the formula becomes like this: y = offset1 + factor*(value-offset2).
For example, I want to plot 62.5MHz clock frequency (6.25e7) and room temperature (31) on the same scale.
I would plot the frequency as is, and plot the temperature like this: y = 62.5e6 + 10*(temperature-31).
In the current scheme, I have to fuse offset1 and offset2 into one offset number (62.5e6-10*31).
This works as long as I do not need to adjust the value of "factor" (say from 10 to 100 if I want to make the variation of temperature look bigger).