As @ChopStick mentions the key is exceeding TP to draw down MPA and there are different ways to do that. The types of breakthroughs possible are discussed in this article –
Breaking Through the Xert Way! – Xert (baronbiosys.com)
Scan through posts in this thread to get an idea of the possibilities –
Let’s See Some Recent BT’s - General - Xert Community Forum (xertonline.com)