All MMF, bonds and cash accounts/funds will be interest.
Therefore any Investment Trust, Open Ended Fund, ETF etc. that is composed solely of bond, cash, debt etc. and is outside of a tax wrapper will be also liable to interest rather than dividend tax, regardless of the platform it is held on.
However, in the case of mixed Investment Trusts, Funds, ETFs etc. where the percentage of bonds/cash like instruments is no more than 60%, then they would still qualify for dividend tax, rather than tax on interest.
For example: -
Personal Assets Trust = Dividend Tax
Vanguard Life-Strategy 20% Equity = Interest
Vanguard Life-Strategy 40% Equity = Dividend Tax