Long time reader, first time poster. I have an older model RT1200 trimmer that I use on my XL650. Clearance on each side of the trimmer is an issue, so if you run it in station 4, you won't be able to use stations 3 or 5. Here is the current setup for my case prep toolhead:
Station 1 - Dillon Universal Decap Die
Station 3 - RT1200 w/ trim die*
Station 5 - Lyman M die
I decap on station 1, full length resize and trim at station 3 and bell the case mouth in station 5. I have to bell the case mouth because the trim die makes the case neck too tight (.002 or so) to take flat base bullets. I keep the same setup when loading BTHP bullets and have never had an issue.
The asterisk denoted above is because I had to replace the front toolhead pin with a short flathead nail with essentially the same diameter due to clearance issues with the trimmer at station 3.
Also, previously I ran a Dillon sizing/decap die in station 1 and only used the trim die in station 3 for trimming. I set the trim die to just touch the case to avoid resizing again. Maybe it was my inexperience at the time, but I was never satisfied with this initial setup. I feel like I get more consistent resizing and trimming when I let the trim die do both of the jobs it was designed for.
ETA: For .223/5.56, I don't chamfer at all. I let the M die and subsequent 10-15 tumble in corn cob media smooth any burrs out.