I like the part of DS's plan that includes pretesting out of certain units (or even subjects), with the possibility to either join a higher grade level class or getting differentiated work for the units he tests out of. E.g., for math, he takes a pretest, and if there's anything he missed, he stays in the classroom for that part, then he goes to the gifted teacher for the rest of his math.
For spelling, maybe you can suggest that if your child (any child really) gets 90% of them right, they get moved up to a higher level (next year's spelling lists?). Spelling lists should be easy for them to adjust.
Davidson's advocacy booklet is helpful:
http://print.ditd.org/young_scholars/Guidebooks/Davidson_Guidebook_Advocating.pdf Good luck!
