So here is what I want to do. There is a magic item in the mythic magic items which functions similar to the metamagic rods. I have been looking into if it is possible to use the ring of transcendent spells with spells cast from a wand. The ring of transcendent spells is similar to a metamagic rod as there is a metamagic feat called Ascendant spell which turns non-mythic spells into base mythic spells (no augmented versions).
So first I found that a wand can be created with a spell modified by a metamagic feat.
In the Core rule book on page 113, Which can also be found online with similar wording.
Magic Items and Metamagic Spells: With the right item creation feat, you can store a metamagic version of a spell in a scroll, potion, or wand. Level limits for potions and wands apply to the spell’s higher spell level (after the application of the metamagic feat). A character doesn’t need the metamagic feat to activate an item storing a metamagic version of a spell.
So magic items can contain metamagic feats. What about when the item is made not containing the MM? Are you able to activate the wand and use your MM feat to alter the spell? The answer is clearly no as it breaks spell levels and cost.
The modifications made by these feats only apply to spells cast directly by the feat user. A spellcaster can't use a metamagic feat to alter a spell being cast from a wand, scroll, or other device.
What about costly items which are already restricted then? Could the metamagic rods be used when casting a spell from a wand? This answer has not come up with any answers. There is evidence from 3.5 that this is not allowed, but I have not found anything specifically in Pathfinder which states this. I only found one discussion board but had no solution.
So without having an answer to the MM rods working on wands, I am not able to determine if spells from wands can be modified by external effects when the cost has been paid for.
Can anyone offer me the last little bit I need to figure out if I can make a non-mythic wand cast mythic versions when I have paid external costs? I suspect that the answer is no as this was not allowed in 3.5, but Pathfinder is not actually 3.5 and I would like to find out.