Is your feature request related to a problem? Please describe.

Frequently calculating GCR for an array requires a side-calculation based on row spacing. These calculations would be easier and more accurate if row spacing was a direct input to the GUI.

Describe the solution you'd like

Given a GUI input for row spacing. This could be a radio button to allow row spacing or GCR to be used as an input (with the other calculated).

Additional context

There is lots of room for discussion on how to manage interactions between the system design page and the layout page. Additionally whether the radio button is a good idea or just making GCR calculated is preferable.