The link to Architectural Decision Records is empty, but they're present in the repo to look at[0]. Curiously the decision with the most deciders is the implementation of JavaScript bindings[1].

[0] https://github.com/EpicGames/lore/tree/main/docs/developing/...

[1] https://github.com/EpicGames/lore/blob/main/docs/developing/...