We only had roast beef and veg in ours 2 weekends ago and it was delicious.
We cooked our's in my hubby's new toy. This is the thread here: http://camping.com.au/phpbb/viewtopic.php?f=107&t=6278&sid=3490aac9b35442106486764fab48a737
I had two blade roasts totally 2.5kg in our bigger campoven. I put a trivet on the bottom of the campoven to stop the meat sticking and burning. Also added some water and the all important ingredient "red wine"!!!!
We lit the fire about 2pm and put the meat on at about 3.30pm and we ate at probably (a few red wines and I loose track of time especially when hubby & his mates are cooking)...6.30pm to 7pm. If you keep checking it with a fork you shouldn't burn it!!!
We did all the veg in a smaller campoven as we were catering for about 12 people...we put the veg (peeled potatoes cut into quarters & pumkin) in foil with a bit of water in the bottom of the campoven so they were steamed not really roasted. We cooked the peas inside in the microwave and made gravy with gravy granules which are instant you just add boiling water and it was gorgeous. We put the veg on about 1.5hrs before we ate.
Not sure how you would do it with heatbeads as we have only ever done it over the campfire. Ours were also hanging just above the coals so that would make a bit of a difference. Just remember not to put in straight in the middle of the fire or it will burn, we usually put some to the side and sit the ovens on them.
The oven we used for our vegies was a 9 quart Oztrail.
The next morning hubby cooked the leftover veg & meat with tomatoes and onions and it was yummy on toast!!!!
Good luck & I look forward to hearing how it all goes. Doesnt sound like you guys have a great track record if you burn snags but you never know this may be your forte Brad....
There is also a site which is specifically for campoven cooking....Derek used to be a member of this forum but I haven't seen him on here for ages..http://www.aussiecampovencook.com/