At the property-level, Spencer uses XIRR when calculating IRR on a monthly basis and IRR() when calculating IRR on an annual basis. You can see this calculation on the Property CF tab (E22 for annual, and E67 for monthly).
In terms of net profit. Spencer does not calculate net profit at the property-level, although to calculate net profit simply take the sum of the Unlevered (row 66) and Levered (row 87) cash flow lines on the Property CF tab.
He does calculate net profit at the partnership level. You can find this calculated on the Equity CF tab, and summarized on the Summary tab (T32 for Sponsor, U32 for LP Investors).