Not everyone has played the campaigns and knows what a ‘death crystal’ is for example. Even though I’m new to coop, I can play the game decently well and have a lot more SC knowledge than a newcomer (I beat WoL on brutal twice and watch tournaments religiously), I got completely bopped by death crystals and void rifts on one mission without even knowing what they did. I didnt even know they were the enemy since new commanders like Alarak/Zeratul have so many space wizard abilities that look similar. I had to watch the replay and study the last fight closely to figure out what was going on, and that’s just not realistic to expect everyone to do. With the inevitable influx of newcomers to SC as a whole with the COVID lockdown, this is going to happen a lot and aggravate a lot of players.
So I dont really care how you do it or where you put it, but it would be very helpful to at least create an index of novel map mechanics that people will encounter in coop with short videos on what to look for. Fanmade wikis usually just have text that doesnt explain it nearly as well.