PowerBI Desktop Freezes [Not Responding]

I used to encounter lots of performance issues around importing data and folders from SharePoint Online, until I undertook a major optimisation of my Power Query code. I tried to minimise the number of query steps that were generating a refresh of data back to SharePoint. I found that the biggest improvement came from buffering the SharePoint data at the point of pulling the data from SharePoint, like this:

    RET =
        Table.Buffer(
            Table.RenameColumns(
                Table.SelectRows(
                    SharePoint.Files(
                        "https://" & TENANT_NAME & ".sharepoint.com/",
                        [ApiVersion = 15]
                    ),
                    each(
                        // RET
                        [Name] = RET_FILE and
                        Text.Contains([Folder Path], RET_PATH)
                    )
                ),
                {{"Folder Path", "FolderPath"}}
            )
        ),

Since doing this I've had no issues with SharePoint Online performance.