Why on earth would you want to? It's not big, and it's certainly not clever. If you insist though, no, it's not really possible on the stock ecu.
Its not an abf, mk3 AGG stock management on a 1.8l. If you stare you can see some flames, nothing out the back though.
Don't know if it's bad for the engine but seems pointless - there must be too much fuel being pumped in for the combustion process to consume and turn to energy. If it is running rich then that will wash oil from the pistons, cylinders and bearings and will cause engine damage overtime. Whether that's how they do it I don't know, maybe it's just a small injection of fuel at the right time which I doubt would cause any problems.