CONTAINSROWS error in Row Level Security DAX expression

I reviewed the CONTAINSROWS documentation and realized that in my return statement

[ServiceAreaEpicId] in Service_Area_10_Lookup_RLS,

is looking to match one field in a table with two columns. Rather than try to get the CONTAINSROWS syntax right and match on multiple columns, I ended up creating a new variable (sa10rls) to select just the one appropriate column for that match. Here is the whole thing, which now seems to work:

VAR lookupUserID = LOOKUPVALUE(ADUserView_RLS[UserID],ADUserView_RLS[PowerBILogonID], userprincipalname())
    
VAR lookupDepartment = SUMMARIZE(FILTER(UserBusinessSegmentMappingFact_RLS, UserBusinessSegmentMappingFact_RLS[EmployeeEpicId] = lookupUserID), UserBusinessSegmentMappingFact_RLS[BusinessSegmentKey])
    
VAR lookupServiceArea = SUMMARIZE(FILTER(DepartmentDim, DepartmentDim[DepartmentKey] in lookupDepartment), DepartmentDim[ServiceAreaEpicId])

VAR sa10rls = SELECTCOLUMNS(Service_Area_10_Lookup_RLS, Service_Area_10_Lookup_RLS[SERV_AREA_ID])
    
RETURN
IF(
    COUNTROWS(Filter(lookupServiceArea, [ServiceAreaEpicId] IN {"10"})) > 0,
    [ServiceAreaEpicId] in sa10rls,
    [ServiceAreaEpicId] in lookupServiceArea
    )