Providing my own answer:
You can generate an aggregate payroll report immediately after you run payroll. There is a confirmation screen, and in the lower right there is a button to run the report. You are then taken to a screen where you can select which of the payroll reports (each separately available in Reports) to include in your report, which generates as a single Excel file. Very slick.
I will try to screen capture this next time I run payroll, if only for QBO support (it's not a surprise to me that no one remembers this feature exists).
