I have found this resource is great for making a single map Safari Zone, where an Event can change what Safari Zone Pokemon, from Gen 1 to Gen 9 can be encountered. My only nitpick with this is what the encounter versions are displayed as numbers, instead of having a way to label the encounters, so the user experience for the player is better. But it's clear this resource is more for developers, than for players.
This is great to use, if a developer needs a solution to condensing multiple Gens of Pokemon into a singular map.