How long to allow for transfer at Singapore

Hi All,

I've got a business class ticket booked with QFF from Singapore to Paris via Helsinki on 17th September, 2025. Flight leaves Singapore at 21:45.

I don't have the leg from Melbourne to Singapore yet as I'm intending to pay for this leg and the flights aren't listed yet.

Based on the previous week 10th November, the likely flight departs Melbourne @ 12:15 and arrives in Singapore @ 18:15.

I'm thinking that it's likely I'll need to collect my bags and go through customs, book in etc, because they will be separate bookings?

Is 3.5 hours enough for all this? I've got no idea really because it's my first flight overseas. Also, do these flights ever run late so that I could miss the connecting flight?