I can definitely say that on my 2015 BE100 modifications (Synergy Capacitors/Gain Structure/Clean Channel conversion to SS100) made a awesome difference. The Gain Distortion is more powerful sounding, live playing sounds full range, harmonically rich and the "Gain-Structure" have different levels of distortion Middle=lowest/Left=next level up/Right=highest amount (BE-mode) doesn't sound "Dark" but versatile in the studio! I've played in the lowest setting Middle for blues and sounds great to the highest (right position) sounds killer, "Warm wide & focused" responds great to the players style, smooth to aggressive and then there's the "Voice" if you want more Cut (another great tone restructure) also all the great tone shaping from the rear switches, and HBE-mode.
The Friedman BE100 mods and specs amp rundown right there son.
Anyway I'm sure we'll never know for certain about the tone difference of the Mallory & Sozo caps, but I trust Daves explanations on them. No all I have to do is call Dave and see when is a good time to ship my amp for some updates!!! Can't wait, have high hopes for another mod for my personal taste.