Yeah that's what I ended up doing so thank you for your advice, although it was still fun wandering around and getting XP regardless. If this is an issue on consoles though it really needs to be addressed as they wouldn't have the ability to do that would they? Anyway, thanks again!
EDIT:
Just for anyone else who isn't used to CheatEngine like myself:
1. Download CheatEngine 6.4 and install (make sure you customize install otherwise you'll get a toolbar you don't want) from here (open in new tab by right click)
2. Download the Dragon Age Inquisition cheat table from here (open in new tab by right click)
3. Run Dragon Age Inquisition, load your save (would recommend you back up too first), and run CheatEngine
4. In the top left of CheatEngine, you will see:
- Attach to process, select the Dragon Age Inquisition process here
- Open a cheat table, select the downloaded Dragon Age Inquisition cheat table (is a .CT file)
5. Select yes on the prompt that comes up to run script or something
6. The bottom of the CheatEngine window should now have a list of things, such as party editor, inquisition editor, inventory item editor etc...
7. You want to select "Infinite Potions and Free Crafting", (a warning will appear below it and the box will be crossed, indicating it is "active")
8. Go into Dragon Age Inquisition, and travel to a shop. Sell ONE Alpha Quillback Spine only (if you have 2 out of 3 spines, killed all the alpha quillbacks but one didn't drop a spine as DarkAmaranth said)
9. You should now see you have three Alpha Quillback Spines in your inventory in the shop.
10. Exit the shop, and the quest dialogue box should update so that you have enough Alpha Quillback Spines
11. Go back to Cheat Engine, and disable "Infinite Potions & Free Crafting"
12. Exit CheatEngine
13. I would recommend you create a new save completely in Dragon Age Inquisition at this point just in case
14. Finish the quest
