One area where Endless Legend with ELCP stands out is the range of options available when setting up a new game. In most 4X games you have a basic options menu with minimal features and an “advanced” mode that is often underwhelming. Mods tend to fill the gap by offering “expert” settings, but the reliance on mods often leads to issues when updates break them. An elegant solution would be for the developers to integrate these settings directly into the game.

For instance, let’s say the map’s maximum elevation is set to 5 during world generation. Why not allow us to experiment by setting it to 20 instead? Or what if we want each region to be massive, so give us the option to specify a numerical value, like "300 = extra huge," and add 10 minor faction villages to each region? Experimenting would be fun even if the AI would have a hard time to keep up. 

Other potential adjustments could include things like how many technologies need to be researched to advance to the next era, or tweaking the difficulty of victory conditions. For example, perhaps the last five scientific breakthroughs needed for victory could require 200% more science to unlock. The same could apply to gold, diplomacy points, or even the number of territories an alliance needs to control for a win. There could also be military modifiers, such as making cities 50% stronger or weaker, or a specific unit type. The possibilities for settings are endless. 

While these examples might not be perfect, I believe that once you’ve invested a few hundred hours into the game, having access to these quirky settings would improve replayability tremendously. The UI doesn’t need to be overly fancy for this; a simple list organized into categories would be enough.

If the concern is scaring off new players, the solution could be to hide these "expert" settings behind an option in the game settings that is disabled by default.

If this is not optimal then please expose as much as possible for mod making. An example for wacky maps for Endless Legend is the World Generator Full Customization mod

tldr; giving players more customizable game / map / world / faction settings leads to a richer gameplay experience.