Coverage C Limit for Property at Other Residences

I am looking for clarification on the ISO contract regarding the 10% of Coverage C limit for property at other residences. I have three scenarios: Scenario 1: Can you expand on the 10% limitation for property usually located at an “insureds” residence other than the “residence premises” in light of a dual residency situation. If an insured owns a condominium which is insured with an ISO HO-6 policy and also rents a home and splits time between both homes would the 10% limitation apply to the personal property in the rented dwelling? Or would there be no coverage for the personal property usually located in the rented dwelling?
Scenario 2: If a student is away at school and living in a dwelling that is owned by the parents (not the residence premises), does the 10% limitation still apply to the student's personal property usually kept there? Is there a distinction for Coverage between the student being in a dorm, a rented dwelling, or a dwelling owned by the parents for the student's use while at school?
Scenario 3: Are there any additional considerations that need to be taken into account for Coverage C limits for an insured who owns a time-share and spends a week or two a year at the time-share? Thank you for your assistance.