BJCM carrycot - suitable for daytime naps?

[SnapFrakkleAndPop]

I've got my BJCM carrycot and it looks a good size etc. I'm wondering if it would be suitable for daytime naps around the house at least for the first few weeks and very possibly the occasional overnight staf? Obviously if baby is out and about with us then it will have to do because that's rather the point of having one but I wouldn't want to overuse it if there's a significantly increased risk of SIDS. I know you're not supposed to use them for unsupervised naps but do you think it'd be okay for popping baby down for an hour or so regularly?

Also the mattress is foam but no waterproof cover - any suggestions on how to waterproof it?

Its not a ventilated mattress so I dont think it is suitable for overnight sleeping.

I will be using mine for naps when I am nearby though

I was wondering the same thing as I was planning on putting baby in it to sleep whilst downstairs. I might pop and measure it, then buy a moses basket/pram mattress (trim if necessary) and use that. Small mattresses are only about £10 and surely must be suitable for sleeping on?!