Currency Trading UI - Favourites taking up less space

Right now the currency trading UI seems really weird to me

https://imgur.com/a/Y8zVWQe

When there is a limited number of 'global currencies' that players tend to use, it would seem to me to be a rather large waste of screen real estate to constantly have pairings like

currency A to currency X
currency B to currency X
currency C to currency X
currency D to currency X
currency E to currency X

Every trade pairing is taking up double the space it should (-1 for the slot for currency X)

My view on how it should work is that the favourites should probably be just a list of what a player might consider "my normal currencies to trade in", so in this case, I'd be using 5 "slots" of space in the UI listing Blight Scarab, Divine Vessel, GBB, Instilling Orb and Chaos Orb, rather than 8. The "efficiency" of this goes up and up the more favourites a player has.

To manage how to create the buy/sell, what I envisage is this:

At the top of the page, you have 2 empty slots. A blue slot and a pink slot. These are your buy side and sale sides. ("Want" and "Have" in the exchange's lingo)

The user then has to construct their trade:

L-click on a favourite currency enters it into the blue/want side
R-click on a favourite currency enters it into the pink/have side

For both of these steps also highlight the currency with a blue/pink boarder on the selection list

Repeated (same) clicking on an already selected favourite currency removes it from it's corresponding side, blanking the selection
Repeated (alternate) clicking on an already selected favourite currency removes it from it's currently selected side and enters it into the opposing side.

Filling both blue and pink sides automatically (?) takes you to the currency exchange main screen.

You break even for space when you have 3 favourites trading to/from a single common currency. This seems like a no brainer for a slicker interface.