Jadzi, Oracle of Arcavios and Spells with X mana cost
Ingenious Mastery has a Gatherer ruling that says

If you choose to pay one alternative cost, you can’t pay any other alternative costs. For example, if an effect lets you cast a “Mastery” spell “without paying its mana cost,” you can’t also choose to pay its given alternative cost.

The ability of Jadzi to pay 1 to cast a spell is an alternative cost just like &quot;without paying its mana cost&quot; is. If you cast the Mastery that way, you won't cast the Mastery by paying the 2U alternate cost, so you do not get to draw three cards, and your opponent does not get to scry or create tokens.
And X is necessarily set to zero, as per Jazdi's Gatherer ruling:

If you cast a spell with X in its mana cost using Jadzi’s magecraft ability, you must choose 0 as the value of X.

So ultimately, the Ingenious Mastery doesn't do anything as it resolves.