The big issue is with tax liens is always:A tax deed may be redeemed by the owner, directly with the purchaser, within three years(state specific period of time) from the date of issuance of the tax deed, or indefinitely if the owner has maintained possession.Each state can be unique in this and by all means do not make modifications until the redemption period has lapsed, less you get a big thank you from the owner when they exercise their redemption rights.

Some tenants either let it lapse, or cancel it later on.

If you drive through it once a month you can see a decent time lapse of it changing.

I’ve spoke with AON and they confirmed it will continue and the policy will not lapse or get cancelled from too many claims.

The other issue is in your policy it will state that  if the home is vacant for more than 60 or 90 days most of your coverage has lapsed as well..

If a tenant allows his renter's insurance policy required by the rental agreement to lapse for any reason, the landlord may provide any landlord's renter's insurance coverage to such tenant.

I have momentary control of those funds.

This way, if the insurance lapses, I am notified. 

[So the myth that IULs are going to lapse due to rising mortality costs is just that, a myth.

Frank also has the right idea with asking to be added as an additional insured... it doesn't extend coverage to you, but you would be notified if their coverage were to lapse or be cancelled.