Promoting only to final mailed list

I've seen other posts (my own included) wondering if there's a way to delete certain promotions from pieces that didn't get mailed and it looks like there's still no solution to this.  So, I'm coming at it from the other direction of not promoting the original list at all, but waiting until I have the final list then promoting that.

I'm pretty sure I'm overthinking this and would appreciate a gut-check on my plan or suggestions:

1. Create extraction with various segments, save each segment as a separate list (suffix name with DRAFT)
2. In appeal, create Outside Source placeholders named for each of those lists and to create source #'s for those lists
3. Export lists, add column to each and add in source number
4. Combine lists in excel into one master list with source numbers so mail house or giving officers can play with it (remove names for ncoa, recent giving, etc)
5. When master list is final, import a list for each final set of source numbers (suffix name with FINAL)
6. In appeal, change each Outside source to an Inside source and pull in Final list for that segment
7. Promote sources using drop date

Thanks!