Op, I'm actually really taken back that a HV and midwife have told you to cant leave the room even for a minute for a wee or a cuppa. That's just not real life and it's not realistic or achievable!
It's so hard as a new mum knowing what's right and what's not, you're trying to do the right thing and follow all the advice, but also you're their mum and you know what's going to work for you. There are lots of blanket advice the NHS gives to reduce risks, however I would apply these with flexibility and in a way that works for you. It's ADVICE, not a rule - and NHS staff aren't allowed to tell you it's ever ok to go against it as they have to cover their backs. Even if it makes way more sense to not follow it to the letter.
Also, it reduces risk. That's all. Some of these risks are already very very low. But also it doesn't mean it will 100% prevent things from happening either.
The advice is assuming nobody has common sense (as many don't). Really it has to be individualised and won't work for everyone. And also it's not rigid. Just use common sense! My baby once fell asleep on her front while the HV was here and she said it's good tummy time and as long as I kept an eye on her it was fine to leave baby on her front for a nap.
We didn't always sterilise dummies right up to 6 months, because baby was shoving toys, dirty fingers and all sorts in her mouth so why bother sterilising a dummy?
I definitely wasn't always right next to either of them during all naps. I even occasionally left baby asleep in the car on the drive and nipped in to make a brew and come back out again, as mine just woke up at any type of transfer. If I'd moved her inside with me I'd have a cranky tired baby.
I'd think about the risk level versus the need for whatever you're doing. What is actually going to happen if you leave them for 2 mins fast asleep?
Sorry this is long haha I hope it helps a bit though. I was so anxious trying to follow all the advice first time round, and actually I wish I hadn't and second time round I was so much more relaxed as I just went with what I thought instead and trusted my gut. Xxx