-1, the whole point of being mayor is being a tyrant. The cool down is there to prevent someone from being mayor indefinitely, however I think it's fine the way it is. One major issue I could see is of course, being rdmed. As fish said, a admin can set you back to mayor, however given some admins don't always see a request for /setjob or are not on, this isn't a solution for every hour of the day. If you have to rely on the cool down, you already lose a ton of the police force at times, and increasing that may make more people quit being police, which can be very harmful if you were RDMed. I can 100% see high level players rdming people while admits are offline, it already happens.
Also, 2 minutes is more than enough time for someone else to switch to mayor. Generally speaking, whenever a mayor causes a ton of issues usually some other level 50 yoinks it from them. If nobody does, I don't think increasing the cooldown is going to change someone from switching to mayor or not. You'd just be delaying the inevitable by a bit more time, adding a longer cool down doesn't fix the problem of being able to switch back so fast, unless you go above 5 minutes. If you go above 5 minutes though, frankly I think that'd be unreasonable. 15 minutes can literally KILL a mayor's PD force, and again if they were rdmed, they shouldn't be punished if no admin is online to give them their role back. Making it a harsher punishment or giving lower admins doesn't give a solution, I've seen PLENTY of high level players manipulate their way out of rdm cases after blatantly rdming mayors, and again, if nobody is on to set their job, nothing can be done. Letting lower ranks set people to mayor also just opens up more chances for exploitation.