If I am intrepreting correctly, you want the following:
- annual passes
- one-use early entry, not staying onsite
- use of AP discounts throughout stay
- use of MaxPass throughout visit at a cost no greater than the add-on cost of MaxPass to APs
- entrance on two blockout days for the Deluxe AP (first and last days of the trip)
Yeah, you can't have all of these things at once. Here are your realistic options and what you get and give up with each one:
Signature APs instead of Deluxe. Maximum effectiveness of this would be to upgrade before park entry on the Sunday and add MaxPass to the AP at that time. You pay for MaxPass only once and don't have to deal with paying on a daily basis each morning you enter the park. You might be able to enter the park first and upgrade later in the day and get your daily MaxPass cost applied to the cost of your upgrade since you are adding MaxPass to the AP. I never assume such would be guaranteed because I don't believe it is offered in writing anywhere, but CMs have been known to offer this. You have immediate access to discounts. You will not be blocked out during any part of your stay. Should you decide you want to enter the park for any part of whichever your "Day 6" was going to be, you have the option. You lose the early entry.
Deluxe APs, upgrade on Sunday. You will receive a blockout exception for the day you upgrade so will be able to enter the parks throughout the day Sunday. You will have access to discounts and not risk paying extra for daily use MaxPass in addition to annual pass add-on option. You lose your early entry. You also lose access to the parks on Friday and have to choose either to skip that day or pay for single day tickets.
Deluxe APs, upgrade on Friday. You will receive a blockout exception for the day you upgrade so will be able to enter the parks throughout the day Friday. You will have had the opportunity to use the early entry on the Tuesday or Thursday before the upgrade takes place. You will have access to AP discounts on Friday from whatever point in time you upgrade; major merchandise shopping can be deferred to this day. The con is that you will have paid for MaxPass for the previous four days of the trip, and there is no guarantee that will be applied to your upgrade. There have been reports though of CMs crediting multiple days of Maxpass use in such a circumstance, but it is not something to be counted upon.
I would suggest you crunch the numbers for each of these options and look over the blockout calendars for the rest of the year when making the final decision. If you are not going to visit the parks again on any other dates that are blocked out for deluxe APs, then your best bet may simply be to upgrade as early in the day on Friday as possible and hope you are fortunate enough to be credited for your previous 4 days of MaxPass use. Since your AP will be backdated to your first day of park entry regardless of when you upgrade or which AP you upgrade to, it does seem fair for Disney to do this and as I mentioned there are reports of it happening, but since it is not offered anywhere in writing it is not part of policy and therefore not something to be expected or guaranteed.
If I was the one making the decision for myself and I could afford it, I would simply choose the signature APs from the beginning and not worry about the calendar for the rest of the year (I wouldn't plan to go during the blocked out Christmas/New Year's time) and also wouldn't worry about losing one early entry.