Pop up bassinet for 3 month old

Hoping for some Mumsnet advice...

I am thinking ahead to sleeping arrangements for a holiday we have booked for April, when DS will be three and a half months old. We had originally thought we'd take the pram and use the bassinet (which is suitable for overnight sleeping), however he looks like he may have grown out of it by then.

We have therefore been looking at a travel cot, but most seem huge/heavy (to take on a plane)...the pop up bassinets then appear a good idea...but the Ines we've seen are either 0-6 months/when they can sit up or 6 months plus. There's a good chance he'll be sitting up (sod's law he'll start while we're away!) and we'll need one for the summer too...

We've seen this one, but it says suitable for 6-18 months and not for newborns. We're trying to work out therefore if this might be suitable at 3 months? Why is it not suitable for newborns?

http://www.jojomamanbebe.co.uk/koodi-sun-and-sleep-travel-cot-with-black-out-blinds-b7214.html