Guild Wars 2

For example:

I have one of the Books with an infusion upgrade, and would like to later transfer it over to a Capacitor. Would I be able to use a Black Lion salvage kit and 100% guarantee that I’ll get the infusion upgrade back?

I’ve already checked transmutations and know that you can’t transfer it that way, but I’m hoping that you can at least salvage it back so it doesn’t just go to waste.

Can anyone clarify?

You can not.
Salvege doesn’t work for ascended stuff.