Just for everyone's attention, if using the Max Department and Max Reputation cheat, you will need to move to another island and then switch back to see the change. You still will need to do one mission for each of the divisions on each of the islands to fully unlock everything and all the Ingen Database Entries that link with that achievement.
Also when doing this as soon as you complete a contract for one of the Divisions the reputation with the other two will be set to Zero, even with the cheat still activated which obviusly then leaves you at risk of sabotage from the other two divisions now at Zero Rep.
no you dont, i got it working before id even unlocked any other island, you just follow the instructions and activate it before loading the game. For both option 1 and 0 you can simply save the game, activate the options then load that save, and bam, options working.