Thanks for the reminder. After a month in the bottle, my attempt at gluten free graff turned out pretty decent. Now, I can't really speak for how it compares to regular graff because I've never made that, but you get the gist, right?
I didn't really 'mash' oat 'malt' for my batch. It was more like steeping specialty grains... If you want to duplicate what I called my 'LIGHTer GF roasted oats' here's how:
Start with gluten free steel cut oats. (Either Bob's Red Mill or Arrowhead Farms should both offer GF steel cut oats. Oh, and I started with 8 ounces.) Rinse them off and put them on ungreased aluminum foil spread on a cookie sheet. Use multiple sheets if you need to get it all spread out to a very thin layer. Bake at 300*F for 30 minutes, remove and stir a bit and turn them over. Bake at 350*F for 15 minutes and repeat the stirring/turning action. Bake at 400*F for 15 minutes and then stir/turn and allow to cool.
Now, the trick, and I've read this here on HBT somewhere.... You really should put the oats in a brown paper bag, roll down the top and let them sit out for at least a week before using them. It's my understanding that this allows harsh aromatics to waft off. For this reason, I usually just roast some oats every now and then when I'm beered up and bored and just let them sit and waft until I'm ready to use them. It's usually between 1 and 6 weeks.
Oh, and FWIW, I disagree on the honey fermenting out completely. I've used honey in very simple GF beers along with nothing more than sorghum syrup and a small amount very low AA hops. You can certainly tell the difference in the batch with the honey. To get the most out of honey, it should be added either very late in the boil, right at flameout, or after cooling.
I can't speak for maple because my GF GF is allergic to maple too, so I haven't tried it yet. I have found a non-maple maple syrup imitation, so I might try it someday, but I reckon that may be a year or more off.
Candi syrup would likely give a much more noticeable difference in the end result when compared to either the honey or maple syrup, methinks, but I haven't had much opportunity to play with it yet beyond Gluten Free McGee which a quick search should turn up.
Best of luck to anyone who makes use of what little I have been able to share!