I tried once, but haven’t spent the food to see if it’s feasible. I noticed if I fed a L1 Hero other L1 heroes, for example, then fed it to my L3, the chance for special skill is the same. The number of levels it increases to the hero your feeding it to increases. Does it make any appreciable difference if you level up a lower hero before feeding or not? If you ascend a level one, does the chance of special skills increasing go up? My goal is to increase the chance of special skill going up.
The chance of increasing the special skill is tied to the star level and color of the feeders. Same color gives 2% per star, different color gives 1% per star.
Don’t waste your resources feeding fodder
I am going to say that you are not close to the first to think of this gambit. Now, I will point out no one is ever found advising new players to do this.
That won’t change the odds at all. Your best chance of maxing the special on a 3* hero is to only feed it 1s of the same color, preferably in groups of 10. It takes some patience, but I have yet to max a 3* without 8/8 special using this strategy (11 hero sample size).