Most of the time that I've ever used a flush trim router bit has been to trim a melamine edge or something like that, I'm in the process of building an oak dining room table and chairs.
Decided to build the chairs by using a template to bandsaw the blank and then flush trim to shape. Needed 8 legs and fortunately I cut 9.
Took the first blank and using a 1/2" shank 3/4 x 1 1/2 flush trim in the router table proceeded to trim. Much to my surprise, actually scared the hell out of me, as I was trimming down the slender part of the leg, the bit dug in and split the leg along the vertical grain.
Seems I didn't pay enough attention to how close to the line I made the bandsaw cut. Got a little sloppy and some of the cuts were over 3/8" deep.
Needless to say I went back over the blanks and cut much closer to the line. No problems after that.
Vic