SVGHMI: finally found why HMI:Input wasnt't initializing properly: vsprintf takes a list. Also, removed intermediate variable last_val, since edit_value() works on strings anyhow, and in case of formated floats, it is better to workl on already formated value.
<?xml version='1.0' encoding='utf-8'?>
<SVGHMI xmlns:xsd="http://www.w3.org/2001/XMLSchema" OnWatchdog="echo Watchdog for {name} !" OnStart="chromium http://127.0.0.1:{port}/{name}" OnStop="echo Closing {name}" WatchdogInitial="10" WatchdogInterval="5"/>