Every Tongue & Groove joint, no matter where is is used in the construction process, will automatically line up, fitting flush. Machines materials from 3/4" to 1-1/8" thick.
Bearings are HC318DZZ & 698ZZ.
The advantage of the Tongue & Groove bits is they are a perfectly-matched pair in height. This allows changing of the bits if necessary without adjusting the router. Note: Use Sommerfeld's rubber grommet in doing this.