I thought the argument for not returning to school before the summer was that even with half the class in it was still impossible to social distance the DC and teachers. Our primary only managed 8 DC in a classroom in June. My DCs school has smaller rooms than that so could presumably fit less in. When my year 10 went in for a few days there were 6 in his group to ensure no close contact and they all had to sit on their own table in the hall at lunch. How do you envisage part time schooling being possible at all?