I'm SCM and the only integration I have with Payroll/HR is for them to inactivate a test user and for us to confirm our IPAs notify us when it's an approver. I know that AP and Payroll test employee reimbursements and 1099s and W2s run together. We're all expected to run normal month end together - you might want to run a calendar year end and a fiscal year end to make sure all the numbers go where their meant to.
HR has periodically asked me to confirm/deny I have rights to a screen, etc. And have changed my jobs and terminated me in test several times to test various triggers depending on the upgrade.