Unfortunately not.
To get around this, go to Build/Format and choose Hard Disk as the destination at the bottom the window. This will create a disk image that you can bring into Disk Utility and burn from there, where you can freely adjust the speed.
(and having the disk image makes it easier to make copies later on.)
My software:
Pro Maintenance Tools - Tools to keep Final Cut Studio, Final Cut Pro X, Avid Media Composer and Adobe Premiere Pro running smoothly and fix problems when they arise
Pro Media Tools - Edit QuickTime chapters and metadata, detect gamma shifts, edit markers, watch renders and more
More tools...