Simple workaround solution that I discovered is to use Google Sheets with SuperMetrics add-on. Let SuperMetrics crab data from source(s) and structure it to table(s) in Google Sheets. Then publish spreadsheet as Excel and use the link as web file connection in Sense.
SuperMetrics Pro version will cost around 50€ per month depending on purchase model. Small price to pay compared to QVSource connectors or to hassle one has to go through with REST Connector.