How does the UA Lore Mastery Wizard's Alchemical Casting feature interact with the Spell Sniper feat and the Sorcerer's Distant Spell Metamagic?

Question

This question comes from recent discussion in the question "What is the maximum distance you can cause damage from?"

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The Unearthed Arcana Lore Mastery Wizard gets the Alchemical Casting feature which states:

[...] When you cast a spell with a spell slot, you can expend one additional spell slot to augment its effects for this casting [...]

An additional 2nd-level spell slot can increase the spell's range. If the spell's range is at least 30 feet, it becomes 1 mile [...]

I'm wondering how (if at all) this feature works with both the Spell Sniper feat and the Sorcerer's Distant Spell Metamagic:

Spell Sniper

When you cast a spell that requires you to make an attack roll, the spell's range is doubled.

Distant Spell

When you cast a spell that has a range of 5 feet or greater, you can spend 1 sorcery point to double the range of the spell.

Do these allow you to make spell have a range of 4 miles, 2 miles, or still only 1 mile total?

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Note that I am already aware that ordinarily the Spell Sniper feat and Distant Spell Metamagic work together, this is supported in the question "Does Spell Sniper and Distant Spell quadruple your range on attack spells?"

Answer 1

4 miles

(based on an optional rule)

From my understanding alchemical casting, spell sniper and distant spell metamagic are 3 effects that all apply to the spells range. All these effects happen simultaneously. Xanathars guide on page 77 states (this is an optional rule, as most rules in xanathars are mere suggestions):

In rare cases, effects can happen at the same time, especially at the start or end of a creature's turn. If two or more things happen at the same time on a character or monster's turn, the person at the game table - whether player or DM - who controls that creature decides the order in which those things happen.

Assuming it is the players turn and the player chooses alchemical casting to apply first, then the range of the spell has "become" 1 mile. Then the player can choose to apply spell sniper, which works based on the range of the spell which is now 1 mile. Now the spell has a range of 2 miles. Now the last effect applies, which is distant spell metamagic and the distance of the spell becomes 4 miles.

Answer 2

4 miles.

Note that Alchemical Casting states (emphasis mine)

If the spell's range is at least 30 feet, it becomes 1 mile.

Note that the range of the spell itself is what is changing. It would be as if the original range of the spell is erased, then replaced with 1 mile. It is to this 1 mile range that the other features apply.