But seriously, how do you insert a 3/4 measure in a 4/4 song when you're in arranger mode?

When I owned the Solton X1 - which was a decent sounding keyboard - but was unpleasantly heavy and had so many repair issues that I had to send it back three times - it had a reset button making it easy to start over after beat three.

With Yamaha, you have to stop and then instantly start over at beat three. If you miss something, you really ruin the song with awkward silence and you have egg on your face as a performer.