"And I don't see a way to browse for the location when you first create the file."
Yes, you got to Name the file and put it where you need it to go. Don't rely on the Express set up; there is a step to See the Details, or use the Interview setup process as your alternative.
If you Restore, you Always get to Put it and Name it. Please see my attachment.
"Is it possible to change the default location?"
ini files = initial settings.
"Web search shows it used to be in QBW.INI but that doesn't exist anymore"
Uh, yes they exist. Open any QB File. Use F2, and then use F3. Here is the Files tab, and you see the list and the full path here and use Go To, to open them, even.
"Didn't find it in the Registry, either."
It's a File, not in the registry.
"If it's hard-coded, anyone know if using a folder SymLink named C:\Users\Public\Documents\Intuit\QuickBooks\Company Files that points to the remote folder will bother QBE or QDBS?"
You don't "point" to a remote folder. You would be using the file from the remote location, which typically makes it Local, if you are using a Remote connectivity tool. Or, as you asking about Mapped drives? A Remote Session means everything is local "there" and you are connected to them. And that makes .ini files harder to manage, because it isn't Your File at all, and they are not Your settings. It's like Remote Printing. Some remote connectivity services let you print to your own Local printer, and with some, every time you print, you are printing to a printer located in the Remote office, because that is the Locally Connected printer.
QB doesn't really control Remote systems. It suffers through them.