I think we'd need kids in for 2 days, then a day in between off (teacher PPA and time to allocate/prep/respond to all the online learning that is still going on otherwise alongside the in school learning). The 2 days work in school prepares them for the work they then complete at home. The 2nd shift then comes in later in the week to do the same.
I went for a walk earlier and dithered over this option. Maybe alternate year groups? R, 2, 4, 6 in for 2 days, 1, 3, 5 for the other 2 days. Those two days set up the 3 days at home. Or, we go French and Wednesday is a day off for kids!
Positives - every child gets some face to face teacher time. So, from a safeguarding perspective, we get eyes on all children. Also obviously the academics, in so much as education will be happening.
Negatives - doesn't fit as a childcare thing at all. Not sure where key worker children of the 'not your day' year groups fit.
I taught year 6 for six years by the way, so I genuinely think that a day or so would do it. I'm not talking from the pov of not ever having done transition. I also think that if they have to come back into smaller groups, not spending time with all their mates, not spending time with their usual teacher etc, then half the emotional stuff will be impacted even further.