you might be right, but the average waiting time that worked good for my pcb exposure was about 1-2 minutes,so i dont mind waiting this time.at least i dont need to be faster than this..also the time depends on how many transparent sheets you place on the pcb(to achieve darker black),again this depends on how good the printer prints solid black on the transparent sheet.here in greece i cant find transparent sheets for inkjet printer at reasonable price so im printing on semi-transparent paper that increases the exposure time also..but again that's is not a problem..
one thing i dont know is how harmful that kind of light is for humans..i really dont know..
john.