One of the great features of the iReal pro player is that each time a song (or loop) is started "from the beginning", a brand new track is constructed before the count-in starts.

For loop play, that means you would also have to reselect the section you wish to loop.

But, try this: open the song in the editor, select the section you want to practice-- COPY
Close the editor, re-open the editor, select NEW SONG - blank.
PASTE the section you saved into the new chart. SAVE
When you're done practicing, you can delete the chart.
)BOB