So, when it comes to the answer to the OP:s question, the answer is “no, magic find does not affect crafting”. Because magic find only increases the chances of items being blue. Magic find does not increase the quality of the magical properties.

Does Magic Find effect Rune drops?

No, magic find has no affect at all on rune drops. You are just as likely to get an Ist from a countess with 0% mf and 400% mf.

How does Magic Find work D2?

How Magic Find is Calculated in Diablo II: Resurrected. All loot items dropped from mobs or containers in D2:R have a native chance of rolling at various item rarity qualities. The affix “Better Chance of Getting Magic Items” increases the chance of that item being Magic, Rare, Set or Unique, based on that set chance.