Without getting too deep into the weeds, I'll just say it's really hard for me to evaluate small differences in my beers. If we can't share our anecdotal experience, there's really no point to the AHA forum. I'll just say if you do try to evaluate two different methods, try to keep an open mind, because it's likely you'll just see what you want to see.
I strongly suggest against doing A/B taste tests, and do ABX triangle tasting. Have someone else pour the beer, and better yet find people you trust and have them blind-taste it for you. I could easily discern differences in the study I did recently when I compared A to B, but struggled telling any difference between A B and B again. Most judges could tell the difference between the two beers in the ABX analysis, so it's not impossible to discern subtle differences, just that I can't do it.
If I think there's a subtle difference in ester/phenol character from adding dextrose later, either I'm completely wrong, or the difference is actually huge, otherwise I would've missed it completely.