We met with SKGP's teachers at back to school night.
For the most part, I was right that the combined program is a hack to get around attendance requirements. However, there is some advantage, too.
She arrives to Ms. Johnston's (combo 1 & 2) class in the morning, then after roll is sent to Mrs Osborne's (1st grade) class, where she stays until 1:30 or so. At that time, she regroups with the combo class for enrichment. The enrichment programs include PE, math, creative writing, and social studies. They do two day programs (MT or RF) and then rotate to the next teacher.
(Therefore, she spends about 2 hours with Ms. Johnston every 3.5 weeks.)
So, for the most part, she's a first grader, but she's doing the enrichement programs with second grade teachers and working at the second grade level for an hour four days a week.
She also gets to go on both first and second grade field trips, which sounds pretty good to me.