Go to drawer box designer take a standard drawer box with a 1/4 bottom.
Remove the front
Left and right sides are butt joints to the back all insets are 0"
Inset Bottom 3/4"
Left and right sides flush
Bottom Settings: Back bottom flush ,Front front flush. Left and right full dado. Dado depth 1/4" all tenons set to 0"
Every thing looks fine
Now change the Left and right Front insets too Lets say -3/8"
Every thing Still looks fine
Now change the Bottom front inset to -3/4
Take a close look at the back of the drawer.
If you change the The Bottom settings to Blind dado and keep all tenons at 0" IT still wants to leave a tung for the back side and front side Even when all tennons are set to 0"
I think the tenon settings you are referring to are the tenon shoulder settings. At 0 they will just create a full dado. To remove the tongue on the front and back simply change the construction to Butt. If you have Blind Dado selected for the front and back of the bottom then eCabs will always create that joinery.
Kerry
Did you make a dwar box as described in my post? All of the sholder settings are set to 0" But when you set the front insets to -3/8 and the bottom front inset to -3/4 with a full dado set for bottom the back of the bottom looks like it extents by the same amount less the thickness of the back.Then when you set a blind dado for the bottom there is a sholder on the back left side and right side even thogh all sholders are set to 0".