Multiple row Context within Iterators

Hello Community,

I am trying to compute a table using DAX with date wise sales and its running average of last 5 days. 

I have this following code which works fine. However i reached here after some trial and error and i am unsure why the other DAX which i tried didn't work when i thought they should work (based on my limited knowledge and experience)

DAX - Version 1 - Works Fine

running_avg_table =


VAR date_sale_table =
    SELECTCOLUMNS (
        SUMMARIZE ( Sales, Sales[OrderDateKey], 'Date'[Date] ),
        "Date", 'Date'[Date],
        "sales", [Sales Amount]
    )
VAR final_table =
    ADDCOLUMNS (
        date_sale_table,
        "running_avg",
            AVERAGEX (
                FILTER (
                    date_sale_table,
                    [Date]
                        >= ( EARLIER ( [Date] ) - 4 )
                        && [Date] <= EARLIER ( [Date] )
                ),
                [sales]
            )
    ) 
RETURN
    final_table 

Desirable output - 

DAX Version 2 - Unable to understand why this version do not work.

In this version, I have brought AverageX function in a seperate variable and used Sumx as an outer function just to have multiple iteration of date_sale_table.

running_avg_table_1 =
VAR date_sale_table =
    SELECTCOLUMNS (
        SUMMARIZE ( Sales, Sales[OrderDateKey], 'Date'[Date] ),
        "Date", 'Date'[Date],
        "sales", [Sales Amount]
    )
VAR avg_last_5_days_sales =
    SUMX (
        date_sale_table,
        AVERAGEX (
            FILTER (
                date_sale_table,
                [Date]
                    >= ( EARLIER ( [Date], 1 ) - 4 )
                    && [Date] <= EARLIER ( [Date], 1 )
            ),
            [sales]
        )
    ) 
VAR final_table =
    ADDCOLUMNS ( date_sale_table, "running_avg", avg_last_5_days_sales ) -- invokes context transition
RETURN
    final_table 

Output from DAX 2 

I have two queries with respect to this piece of code.

1. I think there are 3 row context being created when defining "avg_last_5_days_sales" measure. First by the outer function Sumx, then by Averagex and lastly by Filter function. However, i think the DAX recognises this to have 2 row context only. This is evident from the fact that i cannot set "2" as an integer value for the 2nd parameter of Earlier function. I am not sure where i am going wrong with this?

2. Why variable "avg_last_5_days_sales" when used as a measure call in "final_table" variable do not yield the average of sales for the preceding 5 days period?

My argument here is that as this is a measure call, it should have "calculate" as the implicit outer function.

Addcolumn being an iterator should result into context transition in that case and should provide the average of the last 5 days sum. When i use Averagex function directly in the final_Table (as in case of correct DAX version), i am getting the correct answer.

Supporting Material / Info - 

One can refer to the PBIX in the following drive link

https://drive.google.com/file/d/1zwmulRDtPdA766Q6ixruYKDVFR6jddu-/view?usp=share_link

From Table relationship perspective, sales is a fact table, while date is a dimension / date table. 

Thank you everyone for your time investment in attempting to help me

Cheers

ARU