The metamagic feat affects the base spell (shadow conjuration/evocation) and increases its level as appropriate. The level limit of mimicked spells stays the same.
Casting an empowered shadow conjuration, for example, would require a 6th-level spell slot and would empower a mimicked 0-3rd level conjuration spell.
EDIT: Bah, typo'd and corrected.
The metamagic feat affects the base spell (shadow conjuration/evocation) and increases its level as appropriate. The level limit of mimicked spells stays the same.
Casting an empowered shadow conjuration, for example, would require a 5th-level spell slot and would empower a mimicked 0-3rd level conjuration spell.
Minor correction: an empowered shadow conjuration would take up a 6th level slot.
The metamagic feat affects the base spell (shadow conjuration/evocation) and increases its level as appropriate. The level limit of mimicked spells stays the same.
Casting an empowered shadow conjuration, for example, would require a 5th-level spell slot and would empower a mimicked 0-3rd level conjuration spell.
Shadow Conjuration is level 4, Empower is a +2 adjustment. 6th level slot.
The rules don't indicate that you can 'pre-metamagic' a spell with the shadow conj/evok spells. So you would be in the clear saying no.
If I were the GM I would allow it if they had the feat. For example wizard has the Metamagic Feat: Extend (not a rod) and wanted to cast an extended (+1) Communal Mount (2) [totaling 3rd level spell] via the 4th level Shadow Conjuration Spell - I think they should be able to do so.
That's a quite reasonable house-rule. GM discretion, of course.