But One Drive, Dropbox, and Google Drive are all sync'd to your local drive, so you'd essentially be pointing to your local/network directory instead of a remote drive...

Google Cloud is the only service that is truly cloud storage and my understanding is that you can map it as a local drive.  So long as you are able to map the drive, it would work as if it were local and Lacerte will not know the difference.  That leaves your internet connection to be the only variable, IMHO.