I think teenage DC need some time getting up to mischief before focusing back on studies. I wouldn't send in for the full 6 weeks. Mine are doing okay, working quite hard most days, focusing on core subjects enjoying a slightly alternative curriculum based around the skills of each other with coding and music.
Bubbling just under the surface is a lot of emotion and fear. They don't have the life skills to manage what's going on, neither do I for that matter so we plough on. DS2 (14) is almost refusing to leave the house. He won't take the dog out round the park on his own. It's not a beligerant teenage refusal, it's a fear of going out. He needs to find his own feet again, let off a little teenage steam, go and buy too many sweets and sugary drinks at the shop then have belly ache, hang out with friends just being children. All those things that teens do that will re-introduce some normality.
Getting vulnerable children back into a school room, initially, will be more pastoral support than knowledge based education. That cant be done by volunteers. Some children will have been very isolated without access to tech, living off food parcels, poor parent/ carer ability to support, possible abuse scenarios where the situation has heightened the abuse. Educationally there will be a gap between those who've engaged and those who haven't. Set based education will have to be adjusted. For a child who hasn't engaged to just be shoved back in a group of those who have being taught at a level to challenging for them will just disengage them further.
I'd rather that the when back at school in September (I hope) that children make use of pre and post school open study sessions. Most secondarys seam to offer them, particularly for exam years. So children do their lessons and then anything they find tricky or if they want to do homework at school they can go to the relevant subject study group and get support.
From September if we aren't back in school, I'd like to see DC having access to online open study sessions by subject. Not set based, virtual drop in sessions by subject that can back up the video tutorials and worksheets/ online lessons they've done to help support they've got good grounding on the work they've done.