Wait i didnt know matt also stood for frank?? When exactly was that?? (Era?)
All Black Parade era I believe.
There was this time in March 2007 at Wembley, London, when Frank apparently played the whole show on his knees or the floor bc he was so sick. He never came back on for the encore, so Matt played instead.
Then there was the time Frank had to fly back home from the UK bc his grandmother died, in Nov 2007. I found that info from this livejournal thread so I don’t know how accurate it is. It also says Matt filled in for P!ATD sometimes :D