Cunning way to detect differences in sound

Though nulling and fast switching blind comparisons are adequate they sometimes fail in one exact situation: let's say you want to compare 2 versions of the same synth with randomly modulated lfos where you do not have a possibility to switch off modulation. The manufacture claims identical sound but are we obliged to trust? Definitely,no way. The trick is to instead of comparing raw sound from 2 versions compare sound processed by the same low fi reverb as it will exagirate the differences. Let's say version2 has some resonances in highs unlike v1. As reverb has own resonances they partly coincide with those from v2 and those coinciding will be stretched in time making them well heard whereas nothing will be exagirated for v1 in which case highs will be just more diffused. This method works quite well where it's difficult to detect differences.