I don't have any set model specs and the jigs in my shop allow me to build to any neck specification a client might want. As a result, I find myself adjusting my fingerboard dimensions (scale length, nut width, string-spacing, taper, string setback, etc) on almost every build!
I've found it useful to do these calculations in a spreadsheet that I can share with my clients, so that we can establish the exact specs for their guitar. Some players like wider string spacing, some less string setback from the edge of the fingerboard at certain positions -- every player has their own preferecnes. This spreadsheet helps to sort out the correct dimensions to give the player exactly the spec he/she is looking for.
The spreadsheet is accessible here --> Download Fret spacing, fingerboard taper, setback calculator
The cells in blue font are user changeable and are where you enter the proposed specs for your instrument. You can enter in metric or decimal inches, or you can enter a formula to convert, say, a spec given in inches (which is pretty common in factory literature) to metric (which is how I build). The calculations are then automatic. If you don't want equal string setback on both treble and bass, you can fiddle with string spacing at the nut to give you the desired setback at the nut for one side, then all other positions are calculated for that same side.
Once the spec is agreed with the client, this sheet becomes an invaluable resource during the build.