Have the ability to alter ltscale, psltscale whilst in the Plot Layout tab.
With this ability you can then preview the print and see what changes have been made. re-adjust if required and plot.

Normally i have to cancle the plot, make changes to ltscale, psltscale etc then go back to the plot manager layout tab and preview the plot again. If the changes are not acceptable, repete the process untill it is.