Yes. I would be very happy to see mask wearing in schools. DS is 13 and wants to wear one.
I think at the very least schools should be encouraging those pupils that are happy to wear them, to do so.
I do think there are different considerations for primary/secondary and think the arguments for it are stronger in secondary - due to teenagers spreading it in the same way as adults, and the settings being much bigger. Plus the children are older in terms of how they deal with things/can understand better not to keep touching it/keep it clean etc (I know that might not happen in all cases!).
I get that a lot of people are anti-mask and it would lead to lots of battles if they are made mandatory, I don't know how teachers would feel about having to enforce that, is it another stress for them?
So to answer your question I would welcome them being made mandatory in secondary schools, but think a reasonable compromise would be to encourage them in all schools and see how things go from there.
I would like to see teachers wearing either a mask or a visor too (I know visors aren't as protective as masks but think they are better than nothing, and they don't hide facial expressions/muffle speaking in the way that a mask can, so again as a compromise I think they would be a good idea).