Do not rely on rentals. If you can rent it take it as a bonus. Multi risk currency mortgages are not suitable to all for reasons
1) Currency fluctuations ( obvious )
2) It mostly targeted to high earners/net worth/ & earnings in different currencies.
3) The provider will have a manager who will be shifting the currency periodically & the cost of doing this has to be taken on board.
4) The insurance premium is quite high & the big question is will they pay up if the need arises. I doubt very much