Please Do Not Make Bestiary Core, PoE is Complex Enough
The leveling recipes are by far the most underwhelming ones, and they don't help new players all that much. I think i've tried out 4/5 leveling recipes and ended up using Two of them, the quicksilver adrenaline one and the Helmet all res one, and I'm somewhat of a new player, So what if i can roll a Str helment, i've got the same chance of getting something useful as if i'd just found it on the floor but I've gotta catch 2/3 beasts with the right type just to roll that dice, it's just a waste of time.
Beasts are too random for me to learn anything about them while leveling, Outside of the Adrenaline flask which the game flat-out guides you on how to make, every other leveling item is a shot in the dark at best as to whether you can make it or not.
Catching all the major Act boss/type uniques was a good way to go about gating recipes behind them as these are Big guys you're going to want to catch if you can, but i need the act boss + 2 or 3 other mobs Just to make one item that I don't know what it is Until i've caught it, and then if i want to make More as it's probably a shit item I have to go re-do that boss and capture more mobs just for a chance at it, where-as i could have gone into the next Act already and for the most part found a better item.
Now i'm not saying it shouldn't go to standard, I like some of the recipes (Really like the five new prophecies one, probably my most used one) but the current system is just way too bloated and not user friendly, I just finished my atlas and killed shaper last night, the first time i've done so in PoE, and the highest type of recipes I've unlocked so far (and i capture every Icon'd beast) are the three portals for the Avian, Crab and Cat aspect bosses. I've heard of these cool recipies like Reroll a Map, or add 8 mods too it, or imprint an item, split an item, turn the sockets on an item white, these sounds cool to me but I don't have the foggiest idea of how I go about getting these. https://www.u4gm.com/