Export Location Changed

Don't know if this is made correctly, but I copied some bits of other scripts together to make this: it exports to an Interactive PDF and goes to the same folder as the document. I am only a beginner at scripting, so if any of you see an improvement, I would love to know about it. But it seems to work for me so far.

IDdoc = app.activeDocument;
if (IDdoc.saved){
thePath = String(IDdoc.fullName).replace(/\..+$/, "") + ".pdf";
thePath = String(new File(thePath).saveDlg());
}
else{
thePath = String((new File).saveDlg());
}
thePath = thePath.replace(/\.pdf$/, "");
name1 = thePath + ".pdf";
app.interactivePDFExportPreferences.properties = {
                    exportAsSinglePages: false,
                    exportLayers: true,
                    exportReaderSpreads: false,
                    flipPages: false,
                    flipPagesSpeed: 5,
                    generateThumbnails: true,
                    includeStructure: false,
                    interactivePDFInteractiveElementsOption: InteractivePDFInteractiveElementsOptions.INCLUDE_ALL_MEDIA,
                    openInFullScreen: false,
                    pageRange: PageRange.ALL_PAGES,
                    pageTransitionOverride: PageTransitionOverrideOptions.FROM_DOCUMENT,
                    pdfDisplayTitle: PdfDisplayTitleOptions.DISPLAY_FILE_NAME,
                    pdfJPEGQuality: PDFJPEGQualityOptions.HIGH,
                    pdfMagnification: PdfMagnificationOptions.DEFAULT_VALUE,
                    pdfPageLayout: PageLayoutOptions.DEFAULT_VALUE,
                    pdfRasterCompression: PDFRasterCompressionOptions.JPEG_COMPRESSION,
                    rasterResolution: 200,
                    usePDFStructureForTabOrder: false,
                    viewPDF: false
                };
IDdoc.exportFile(ExportFormat.INTERACTIVE_PDF, new File(name1), false,);

I totally rely on Default Folder on a Macintosh for setting up which folders are used when, as @Mike Witherell mentioned. It's been very well supported over the past decade or two I've been using it.

https://stclairsoft.com/DefaultFolderX/

The only thing InDesign can do, which is limited, is Preferences > File Handling where you can choose whether to relink to Original Link Folder or Most Recent Relink Folder. 

I wish, along with you, that the application/andor/document could remember save and export locations particular to each document. 

Some people recommend this if on macOS:

https://stclairsoft.com/DefaultFolderX/