I always found the "flex" method was most indicative of props and costumes. Of course, the CFC cards are of different thicknesses, some almost as thin as base cards.
This is the method I go with as well, and it saves you money in unopened packs. Considering its a guaranteed two per box with the HBP it's nice to know that you got everything. I know collation was horrible with POAU, but am I correct to think that its only possible to get two per box with HBP?
The seller of the collection mentions that she has a master set for every release so it would be awesome to get pictures of the whole collection. But hopefully she will just continue to list more items. Its funny to think that the ones listed might be her least favorite or duplicates

especially with the amount of Radcliffe, Watson, and Grint's she has listed its nuts.