Marc's S. new bits cut 1/2" deep his old sets (CMT/Freud) cut 7/16" deep ) that's the neat thing about the magic number 4. it can be use on all of them.
When you mill the stock the 7/16" or 1/2" is gone to speak about because of the joint.
!/2" overlay is the standard for most hinges(overlays)
" depends on type of wood " the number 4 works on all panels, it's best to make it 1/16" smaller on the panels so it can float just a little bit..
No math needed just the magic number -4 on the parts,,
Once you know the opening or overlay you want, take the -4 to them and they will fit every time...the rails are the only part that you need the 4 on ,the stiles are always cut to the right size ,with the overlay added on 19" tall door would be 20" tall stiles..
But always start with 5" or 6" wide stock, do the mill work and than rip all the stock to 2 7/16" wide, than you end up with all 4 parts for the door..the panel needs the magic number 4 on all sides so it can fit right in the door parts..
If you don't move the router up or down you don't need to sand the door parts the norm..
I know my inexperience will probably show here, but I don't understand the magic number 4 system. (I can't find it in the links.)
Also, it looks like the Summerfeld's plans restrict you to a 2.5" stile and a .5" overlay for their template to work.
The Freud formulas allow for any amount of overlay, stile width, tenon length and panel expansion amounts (depends on type of wood), just plug in your door height, width and the tenon length and all dimensions are given to you.