In Historical low prices section of the game, where there are the lowest 3 prices of all time, you can't tell for what DRM it was. And that really makes a difference.
For example a gog key of a game that was giving by Amazon Prime sold for a couple cents, while the Steam version of the same game never went below 2$.
So if you can add the DRM logo next to the store's name in Historical low prices section, that gonna be very helpful.