I know, I know. They are supposed to be applied once and never extracted but why? Most liqueurs are from events or gachas that will never be re-released again and they are heavily marked up on the auction house (for example: thundersurge can run 80m/binding crescent around 30m). In lieu of scythes, I find that some of my liqueurs on my staff and chain would've been better suited for the scythe but they are stuck and frankly, probably won't be used again.
TL;DR: It would be nice to have the option to extract the liqueurs or have the ability to transfer them to your other spirits at the very least.