It looks like Dresden-Riesa has not received any Improvement for Scenario Planner in TSW4. - There are no new Start and Finish Points. - You can't send Trains into Portals. - Connecting Paths is of limited use since you can only use each Platform in one Direction. As an example, it is not Possible to travel from Meißen to Dresden Hbf and back again. - It also doesn't seem to Work to send an AI Train and your Train from the same Location at different times. I wanted to build a Scenario with a Start Time of 5 p.m. In which an AI BR 146 should have already left the Station at 4:55 p.m. and my Br143 leaves at 5 p.m. and well... It seems Dresden-Riesa is treated the same as any other Pre-TSW4 Route when it comes to Scenario Planner. Edit: The Thing that disappoints me about this is that DTG claimed DRA will have all the new TSW4 Features and Matt (in one of the Preview Streams) said that TSW4 Routes have a lot more Options in Scenario Planner compared to the older Pre 4 Routes.
