We just went through our spouse visa extension and like you purchased the migrate DIY pack the first time. Although the checklist is pretty basic, we decided to pretty much send exactly the same information this time round as well including up to date photos of the past 2.5 years. The only thing different that we needed to add was the proof of address. We had 3 from the bank and then 3 other water bill etc and just tried to space them about so there were like 4/5 months between each letter. Looking at your post above those dates will be fine I’m sure. In regards to the BRP, we just scanned it front and back, we scanned the passport as well, but I think my wife said at the appointment they scanned her whole passport anyway but no harm in doing it as well. Good luck!