Arduino IDE has always supported Atmel ICE (UPDI) for uploading sketches. How do you debug with it in 2.0 Beta? I am using AVR128DA28 which has the Atmel OneWire debug supported by UPDI programmers so it should be easy. Looking around the web and at the forums I have not come across anyone else trying to use this method.
Update: Hovering over the debug button I get the message, "Debugging is not supported by AVR-DA Series (No Bootloader)". This uses DxCore by Spence Konde. Is this a matter of configuration or does custom software have to be written by a Core developer to support debug?