Side conversion is especially good as it's a carousel. Convert the non-MW materials while you don't need them, and stockpile the ones that do. I.e. I convert my Tier 3 items till Zee Stories, Incendiary Gossip, Visions of Light and Tales of Terror in an off period. When I need to unleash the MW, I have a good stockpile to immediately get them. Otherwise, I will need to painfully convert through the other materials.

If it's particularly hard to get MW, one way is to gain Notability every other week. One week just to grind the items, and the next week to unleash the MW.