"Interlining" is a service that is put in place to allow 2 carriers to sell a single ticket. As such, interlining is a service intended only for those on a single ticket.

While you may occasionally get some airlines to interline across separate tickets, KLM is not such an airline.

"Non-Schengen to non-schengen" is of no relevance to interlining in this, or any other, case.

"Minimum connection time" is a concept that only applies to single tickets. In such cases, you are covered in case of misconnecting. When putting together your own connection on separate tickets, yiu should instead be maximising your connection time to increase your chances of making the connection separately. Remember, if your incoming flight is late, delayed, cancelled or diverted, you lose your next ticket. Buying a new ticket to SIN on the day of departure will be very expensive.

If you must travel on separate tickets, you should instead arrive in Amsterdam the night before the next flight.