A Question of Attestation: Extracting Evidentiality

Does any language with grammaticalized evidentiality permit extracting the evidentiality-marker with regards to mood and aspect?

I.e. the normal conditional

she killed the monster (I saw it myself) → if she killed the monster (no evidentiality?)

However, with a type of auxiliary, you would have

if she AUX (I saw it myself) killed the monster → if I had seen her kill the monster

For a conlang, we could here permit counterfactual statements not to have any evidentiality marker on the embedded verb, whereas factual statements with counterfactual evidentials will have evidentiality on both.