The claim here is that hydrinos could be part of all sorts of marvelous stuff. including super energy dense batteries, super long lasting paint, and energy from water schemes. Presumably this is because the compounds containing hydrinos have unique, powerful properties not to be easily confused with stuff that doesn't contain hydrinos. You are suggesting that despite these amazing possibilities that substances with hydrinos have, it may be that it isn't possible to determine unambiguously that something has hydrinos in it at all, but those hydrinos are the basis for all these amazing characteristics of hydrino containing materials? mmm.
There are probably at least ten different kinds of telltale hydrino signature. For instance there is the rovibrational spectral signature of dihydrino gas, matching the predicted value.
When it is all taken together it is pretty unambiguous for those with eyes to see.
Yes the quantities involved were too small to be useful, but at least they are detectable.