I'm shooting a 27" arrow with a 30" DL using a QAD rest. Ilike the GTarrows and wanted to stiffen the spine so I cut them as short as I feel comfortable with. I probably could go 26" if I wanted to.

The rest has a lot to do with how short you can go The combination of arrow spine, draw weight, DL, & tip weight is the determining factor in how short you should go.