You're already doing the best thing you can do to achieve better speed. There is nothing else that can help you. Quarter notes(picking a note on the click) at 270 bPM is quick but not blazing. To find your PPS or potential picking speed, just alternate pick (up/down/up/down) tremolo style ie as fast as you can at a consistant pace on one note. That is how fast you could presumably pick even fretting notes or switching strings. Now all you have to do is train your fretting hand to keep up. Like I said you're already doing what you can to improve that. there is no better way. Make sure you are playing the scale as clean as possible, perfect in other words before you move up in speed.