You're so full of contradictions OP.
"getting support with learning,
Such as? I support them with learning. Oldest is a year ahead of where he should be.
straight forward learning,
Again.....?
learning to coding
I don’t know what coding is. I’m ok. "
So when your kids need support with coding, because it will be there homework. How will you be able to support them?
Having an attitude of "I don’t know what coding is. I’m ok." is piss poor. Your kids will need to know coding for school. It's like saying "I don't know maths, I'm Ok"
Also your objection to screen time is
that it's "mainly that they promote sitting still and being boring rather than getting outside and enjoying life."
But then you inform us that your kids "They all do a variety of crafts including bead and needlework"
That's the same, they're "sitting still and being boring". They're engrossed in a solo activity.
My DS15 lives his PS4 and tablet. But also loves camping, skating, fishing, swimming, hiking and dog walking. He grew up with screens and isn't a social hermit. When he was 7 he lived things like water fights, den building, bike rides, fishing, play grounds, football...all sorts.
Your kids will be missing out on something that is a central part of everyone's life.
If you honestly think kids can either only go on screens or have wonderful outdoorsy childhoods... Then you're deluded.