Another area to work on might be the tempi...

You listen to a real orchestra, the tempo is a living thing. It breathes, it flows, it helps out the music rather than just SITTING there...

One way that you can still play in arranger mode but get a bit more ebb and flow into it is to use the accel/ritardando feature, but dial it down until it makes only a BARELY noticeable difference. Then, you use it to speed up into a chorus figure, then relax back down to the 'verse' theme, and things like that. If you have a feature where hitting the style returns it instantly to the basic tempo, this can make for a nice transition where you ritardando at the end of a verse, then 'Bang!' - Straight back to the slightly higher tempo.

BTW, these tempi changes will get recorded by the sequencer, and you can edit them better to taste after the fact if they are not perfect the first time through.

I don't know if your arranger can do this (not even sure if mine will!), but try to see if the sequencer can record tempo changes coming from you tapping the Tap Tempo button. Now, put on a REAL Strauss waltz, with the Vienna Symphony Orchestra or another great waltz king, and just tap along with the record while you record this on the sequencer. Now go in and look at the tempo track... See how MUCH it goes up and down? This might give you an idea how much to set the accelerando/ritardando values to, and possibly the rate that change is going to need to come in.

Other tricks to try are, if your arranger can allow tempo offsets for different variations (or, if not, use the same style in different registrations with different tempi pre-programmed) and have it automatically bump up a couple of BPM as you go to a busier Variation.

Let the tempo BREATHE, and your music will come to life!