Enchantress competitions

how do you propose they do it?

It could be any number of things.

Given starting conditions (or even give everyone the same map) see who gets the fastest win of each type in one week.

Create a ridiculously hard scenario and see who can beat it the fastest.

Fastest levelling of a champion to level 15 (turn count)

Best custom faction/sovereign design, where other players compete 1v1 against submitted faction/sovereigns and see which one has the best winning percentage. (Includes unit designs)

Stuff like that.

How do you prevent reloading?

They could implement a hardcore mode like in X-Com. Idea for later maybe

What about if you have a hardcore mode, and the game crashes?  How does the hardcore mode keep the one and only save up-to-date?

In XCOM it saves after every single action and the player is only able to access this save from the main menu. There is always a risk of the game crashing during a save and corrupting the autosave, however.

I know that TOEE had a hardcore mode, but it was not recommended to use it (by someone on the Council of Eight Modpack forums) because the game crashed too much.

CivFanatics have been running competitions for Civilization since CivIII days. Save/loading in a single player game has always been a problem, which eventually led to mods being developed specifically to play these types of competitions.

That's not a risk if it autosaves the last two turns. If a crash occur during one of saves, revert to the last successful save from the other.

Unfortunately, we currently don't have the ability to mod FE in such a way.