I love Ttatt, I don't know if you have seen this site which has a lot of information about the 'miracle wheat'. It is in support of Russell.
What is interesting is that he promotes the idea that all Russell was interested in the wheat because it showed what was possible in the future paradise. Wt 1909 he states
Assuredly, as our text suggests, when the Lord’s time shall come he will be well able to call for the increase of the grain for the benefit of the world of mankind, whom he so loved as to redeem and for whom the blessings of restitution are shortly to be made available. — Acts 3:19-21.
If it lost it's outstanding properties then using it as an example for future possibilities was pointless.