Making Redundant Blueprint Fragments Useful

I saw in one of u/RagingRaptor177's dev Q&A videos the other day that Wargaming has been wanting to find a use for blueprint fragments that become useless once a player fully unlocks all tanks in a particular nation or the entire game. I started thinking about a system that could potentially work.

Tentatively, I'm calling this Universal Experience (UE), however, "Blueprint Experience/Points," "Blueprint Schematics," or anything could work as a name really.

The idea itself is simple and meant to tie into existing systems without having to augment much outside of blueprints themselves:

Each blueprint fragment can be broken into UE for 1/2 value, to keep the math simple, we'll assign the following values to blueprints:

Universal blueprints = 2 UE

National blueprints = 6 UE

UE can be used to create blueprints of the player's choice or be converted into free experience at a rate of WG's choosing.

To give an example, let's say you've finished the USA tree with 20 national fragments left over and want to convert them into USSR fragments:

20 USA to 60 UE to 10 USSR.

Or if you need some universal fragments, you can make those 20 USA fragments into 5 USSR fragments and 15 Universal fragments.