What is Oracle recommended route to post the Payroll Cost to GL when using Project Costing

Summary:

We are implementing Oracle payroll with Oracle Financials and Projects. Payroll costs can be sent to GL for accounting and Payroll costs can also be imported in Projects.

Should Oracle payroll post the cost only to Projects and then projects should post to GL i.e. Payroll -> Projects -> General Ledger?

Or should payroll also parallelly post the accounting to GL along with posting to project costing?

If costs should be posted to both GL and Projects costing. GL would receive cost from two sources sliced and diced differently. How will this work in GL?
while there are employee who work on project and there are other who don't work on projects? how should the cost be sent to GL if choosing projects route?