Technically, the recipe thing is an IO problem not confined to AE. If you roll in a range, it attempts to give you an IO equal to your level. If it's something like Air Burst that goes up to 50 and you are 50 then that's the level it is. It would be vastly better if it restricted it the level range but no clue if the devs will ever do that.
For other AE info: http://paragonwiki.com/wiki/Mission_Architect_Tutorial
I can't seem to find one, but I thought there was a guide that explained the ins and outs of the AE.
I use to know a lot about it, but I have not played in a long time and am rather lost.
I was rolling for level 30-39 recipes and every last one was level 50. I thought, even if you were level 50, that there was a way to roll for the level recipes you want.
Thank you.