There appears to be a problem with ore generation for Mystical Agriculture in ATM7 2.4.0.

I generated a bunch of new world chunks in the overworld after updating and counted the following blocks using worldedit (selections in the range of 20-30 million blocks from height-min to height-max):

mysticalagriculture:inferium_ore
mysticalagriculture:prosperity_ore
mysticalagriculture:deepslate_inferium_ore
mysticalagriculture:deepslate_prosperity_ore

All of them came out to 0 blocks found

Same problem here in 0.2.10

It's set to be very rare in the overworld but all over the nether. I would suggest getting from the nether then making seeds and or bees to mass produce.