Managed to finish off the Leomon quests before my 2nd gen megas died. Currently on my 3rd gen megas, Vikemon and Darkdramon, and their starting stats are insane. 2ks in each stats plus 25k Hp and 15k Mp but seeing as the balance of the game is completely out of whack, I'm not surprised if a super high level rookie or champion tank them later on. The balance is mind boggling.
It does make the game a constant challenge yet it's disheartening when my megas are having trouble coping with a group of Solarmons in Faulty Ex Machina. I wonder how far my 3rd gen mons can go before needing to reborn and power up. On the bright side, Lvl 4 item shops now sell 20k Hp recovery items so that should help a ton and Etemon stock exchange helps in making some bits.
General tips:
You can see a list of materials that you have collected in the builder menu by talking with Veemon. In that list, if you highlight any material, it will tell you where to generally find them in the descriptions. Though some materials can be farmed easily in specific locations. For example, DigiBamboo is easily available in the Hidden Red House area in Logic Volcano although it can also be found uncommonly in Power Plant #2 in Nigh Plains.
DigiAcid which is used to level up the meat farm to lvl 2 is easily available in Power Plant #2 in a fixed spot near the giant lemons. Upgrading the farm early will open up a 2nd slot for the farm which will help in stocking up meats early on.