AR40+ is amazing, because the chances of blue or higher artifacts/items increases drastically, but it doesn't come without flaws. First issue I'm currently having is certain items being time-gated, so ascending is a longer process to get up to Lv 60+, and then enhancement ores become a lot more rare because of how many it takes to progress. Farm routes definitely become more important around this rank. There's a nifty little tool I use for finding certain monsters or items. https://genshin-impact-map.appsample.com/#/ This map can toggle anything you are looking for on or off and the exact location they can be found. Here's an example of Stormterror's Lair, where I have toggled on the crystal chunk locations and any large hilichurls or abyss mages.