Curious - I would think that, if not using a jointer to flatten edges, then using a sled on a table saw would be the simplest alternative.
What made you choose to edge joint in a planer? Can you post a pic of your setup? Thanks.
These days I use my table saw.
I am not presently recalling why I used the planer. It would have been for a particular operation on a project.
The jig was two 90 deg brackets clamped to infeed/outfeed tables with a step cut out in the middle to allow room for the planer head. Space between the brackets was the thickness of the board.
If I recall the step was about 3in, well within the height of the planer.
If I can recall why I felt the need to make the jig I will update the reply.
I made the jig when I was using my Delta 22-580 planer. I replaced this with a DeWalt 735 about 3 years ago.