This concept was shorthanded to the daybound and nightbound mechanic for Innistrad: Midnight Hunt and Innistrad: Crimson Vow
If all you want is to find one card you can find it but the Vault offers something more by letting you preview what cards would come along with it, allowing players to plot out the next several turns of the game and see if the sequence being offered would get it done
Thankfully, an experienced gumshoe like you knows exactly where to look: Collector Boosters
An effective manabase can't contain only taplands, but there's always room for a few, and the utility on Bojuka Bog makes it well worth being one of them
I might be biased, but I think this card is pretty strong and will do more work than youd expect especially in cEDH with access to cheap or free legendary creatures
Thats sweet, but dont forget that card draw