Any clues for speeding things up to return the location/range of the last
filled cell in a column?

Function LastInRange(InputRange As Range)
Dim CellCount As Long
Dim i As Long
CellCount = InputRange.Count
For i = CellCount To 1 Step -1
If Not IsEmpty(InputRange(i)) And IsNumeric(InputRange(i)) Then
Set LastInRange = InputRange(i)
Exit Function
End If
Next i
LastInRange = ""
End Function