There are a few things you can do for the ridge that is created when there is a nick in the knives. The first method would be to use a scraper and scrape it off then sand it smooth. This works well, but can be very labor intensive if there is a large number of boards. AN easier way is once you get the board to the desired thickness, run the board through again only offset it. I have also turned the board end to end to make sure the ridge is on the opposite side from the nick, and this too will get the ridge out.
What you need to make sure is that the knives are properly aligned (very easy to do on the 734) and the height lock is engaged. I have successfully used this method recently planing an 8' Poplar board, with no after ridge.