I havnt tried changing game modes within a dedicated server at runtime . My gut feeling is this wouldn’t work at least without a server restsrt and the only solution would be to have multiple maps with different port numbers that have the different game modes already set up and just switch/travel between them as needed .
Havnt tried this either I set all my options actually on the executable . It might be possible to send the options either in the name or the options section of the open level node but again havnt done this as I havnt needed to.
If you can explain a bit better what it is your trying to do I might be able to assist further .