I wouldn't support it, no. I really don't see what it would achieve, other than disruption.
What's the point? Every child in school at the moment could theoretically could be incubating covid (I'd hope not, but I'm sure some will be this said )....so what... We shut the schools and then the illness is at home anyway.
That weird theory aside no, I think it's totally pointless, wouldn't achieve anything and I think it's just turned into a political fight between Boris and Kier as to who can do this better (I do think Boris is utterly useless and Kier would be better in charge, but I think this "circuit breaker" is just being used as something to bicker over).
This said, if it happened, I'd happily go in and teach key worker / vulnerable kids, and would be happy to send my kids to their school whilst I did. Or I'd teach from home, which one of my schools is setting up with us all at the moment, in case of class groups isolating, or indeed this.
I really don't support it though, but to be honest I don't support much of any of the guidance/ laws anyway. I think it's all a performative waste of everyone's time which is driving the economy and people's mental wellbeing into the ground. Doesn't mean I don't follow the rules but I think it's mostly pretty stupid. Sorry!