Nitrogen fixers get shut down by repeated N applications, so it will take time to get them to come back. I think a mix like the one described will help you transition from straight N fertilization to a biological method. One way to check is to pull roots and see if they have a microsheath of dirt around them. If they do the biological form may be working, as they need an anaerobic area to work. Roots that come out clean will still be working on an ionic (chemical) fertilizer level. Look up the work of Christine Nichols for more info; she, among others, call them “rastifarian roots”! The economics were close for the two “styles” with last year’s UN32 price, with the bump it may be a net savings. I put about half what I normally would put and had good results, but for a perennial crop of trees we don’t have the same pressure as you would with corn. John Kempf has a number of videos on practical experience on corn (I think it was doubling production in a drought, about multicolor or blue corn). I have seen sulfur burners, but most often they seem to be used to change irrigation water than for fertilizer use. The rate of Ammonium thiosulfate in the mix is rather small, and much easier to apply, so that would still be the best choice, IMO.