@RoystonS: I never had that problem during my testing because I always set Halbeshausen to automatically accept trains (so the "accept immediately" is not a problem) and unlike its counterpart FR802 it also doesn't have to slow down for the trains in front of it.

I still added one minute to the arrival time because even with autoaccept, 6 seconds buffer for a train with penalties disabled is indeed a bit too low.

BTW: I added two screenshots of how I configure the perpetual routes when I start the map. The trains from and to Dreiberg Nord/Süd alternate, so you can always have one direction locked and the other queued there and only check back there every 5-10 minutes to refresh those queues. Which means you only need to focus on the the S-Bahn section Nordtor-Hbf-Universität, the main line Mittelbach-Hbf-Ostwald and the branch line.

FR801 (passing Halbeshausen 4 at 08:13 and Ostwald 3 at 08:23) is a tough train. It only just makes it to the destination in time - with barely a second to spare - if you ensure it has no delays AND you accept it IMMEDIATELY at 08:12:00.