Encounter type

An EncounterTypeCode value set was created to support PHC EMR CS. tgateway.infoway-inforoute.ca/singlesubset.html?id=2.16.840.1.113883.2.20.3.207&versionid=20200331

To note, this value set contains values related to the nature of encounter (e.g. online, telephone, etc.)

Yes, my bad. I always confuse Encounter type and Encounter class.

SNOMED has a classification for encounters: all codes with parent 308335008. It's probably too broad for your specific use case but it shows the use of SNOMED for this attribute.

The ActEncounterCode is for Encounter.class and Encounter.classHistory.class elements to classify patient's encounter "such as ambulatory (outpatient), inpatient, emergency, home health or others due to local variations." Encounter.type is more specific, e.g., Annual diabetes mellitus screening.

Unique - many of them are using local code sets.

You could look at the V3 value set: hl7.org/fhir/v3/ActEncounterCode/vs.html

I suspect many v3 implementations in Canada are using that.

Are they available on CHI Terminology Gateway or unique for your implementations?

I have different value sets in my different Implementation Guides because I have different use cases. I'm not sure what you are asking for, since my value sets won't work for your use cases.