Hi Steve,
There are 16 spaces in each line and you can place bar-lines anywhere.

I took a 4/4 tune, (4 bars to a line, 8 lines long) edited a copy then randomly made a measure 2/4 by adding that on the first space of a bar in the middle of the tune. (2/4 appeared ahead of that bar-line) The player went double-time from that point to the end. If there are three chords in a 4-space measure, and you try to play the tune in 2/4, you'll get an error message. (deleting one of the chords will solve it)

Your charts will "look" better and be easier to read if the bar-lines line-up, the irb-player can still play if they don't.

)BOB