Without JJ2+, team-based routes are somewhat complicated to make. When clients initially spawn in level, they automatically receive all of the server's triggers. This causes problems that aren't immediately noticeable when testing a level offline.

Say you wanted to use trigger 1 where having the trigger off opens routes only for the blue team and having the trigger on opens routes only for red team. You would have to use team start positions that couldn't be reached by the other team. Next to each of those start positions would be trigger zones with ID=1 that cannot be avoided by the spawning players, and those trigger zones would be set to "off" for blue team and set to "on" for red.

When a client spawns initially, he/she will receive the server's triggers. So if the server is on the blue team and the client is on the red team the client, the client is likely to start with routes that only the blue team is meant to use. The typical way of getting around this issue is to delay the spawning players with tubes for around five seconds before they activate the team-based trigger. More complicated levels have the delay only occur the first time a player spawns.

However, JJ2+ allows for a special team trigger that is automatically turned off for blue team and turned on for red team, so a delaying mechanism is not needed. You'll still have to use trigger zones next to isolated team start positions though. Just place a trigger zone event with the trigger ID you want to use two tiles to the left of the bottom-right corner.

With that said, some concepts still require some delaying mechanism even if you're using JJ2+, so use your own judgment.