Sales Invoices Get Advances Button

Looking here, it seems as though this old (ancient?) cscript call is no longer working, exposing the Advances section (shown here with a custom skin). I am also getting weird behavior from the section break collapsing.
There isn’t a function connected to this button or a controller. Is this code abandoned?
I’m not the develop branch from Monday and I’m not changing anything until the dust settles from the yarn debacle.