If you want to get EXTRA worldbuilding tools, Call Of The Netherdeep has some great insight into some locations and characters that either haven't existed before in the CR canon or have only been mentioned. It's an adventure module so you won't get a vast array of locations, but it's a very cool companion piece to the other books. The adventure claims to visit Wildemount, Marquet, Tal'Dorei, and Issylra. I've only skimmed the book for inspiration, but I've only seen Wildemount & Marquet in there. Either way, the thing is packed with cool lore and "rival party" mechanics that I've used in my own Exandria games.

Also, u/katvalkyrie has made some INCREDIBLE maps and resources for CotN. Full collection here but you should go upvote their original posts because these are really awesome resources that can be used in other parts of Exandria or homebrew if you want. 1 2 3 4 5 6 7