Regarding SMI, despite me correcting you with reference to the legislation you are trying to rebut what I stated. I suggest that you read Liability for housing costs (click) at pages 105 chpater 23423.
I did not try and put the OP off from contacting CMO/CSA I was just being realistic.Example 2
Harry lives with his mother who has a mortgage on their home. Harry’s mother dies
and her estate becomes liable to meet the mortgage payments. But she did not
leave a will and her estate is not making any payments. The building society cannot
transfer the mortgage to Harry until his mother’s estate is settled. But they agree
that if Harry pays the mortgage he can carry on living in the home. It is reasonable
to treat Harry as liable for the payment of mortgage interest and housing costs for
mortgage interest are allowed.