Hi
You don't need both one will do the job just fine on ALL bits...the profile of the bit will not need to go all the way into the jig , you just need the edge of the bit to sit it on the edge of the EZ set fixture, I have used the Sommerfeld one for years..
The Peach Tree video is a good one, in one of Marc Sommerfeld videos he show how to use the edge of the bit to set it up easy..
Just a note, the EZ Set jig for setting the height only you will still need to use the fence on the router table and use a stop block behind the fence..
The easy way for me is to use a strait edge, once the bit is set for the height put on a ruler on the fence and just adjust the fence in or out, so the ruler just seats on the edge of the cutter on the bit, once you find that point clamp a stop block behind the fence, once it clamped down don't move it,than move the fence out by a 1/4" or so and make the 1st.pass by the bit,on both parts, use a push block to keep the rip down to a min.
Once you have both parts done move the fence back to the stop block point, now stick on some scrap stock to both parts,right to the edge of the wood, once you have the scrap stock in place run the parts by the bit.
The scrap stock is in place so you can get that very fine edge on both parts..now you can see why using plywood is a bit tricky and not a good way to go..
You can see this trick on the MLCS video below..
http://www.mlcswoodworking.com/orde....com/orderstatus/html/smarthtml/pages/bt_lockmiter.html#lock_miter_video_anchor
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