As a matter of fact, every capacitor removed was measured. All were within 10% of marked value. All originals were Nichicon 85 Deg C rated.
All new caps, Nichicon 85 Deg C 20% tolerance, were measured and within 5% of marked value. Measured values of each new cap matched between the channels. A large mismatch might be noticeable. I heard a significant difference in bass, yet the removed components measured withing spec. Certainly something happening during in circuit operation. Maybe the new caps will settle in and return to the old cap sound? Fun hobby, isn't it?
However, the circuit designer of a mass produced high quality product has to account for normal part tolerance across all active and passive components. An audio amplifier handles a pretty small bandwidth and well designed should not be so sensitive that small component variations cause problems. You can go down the rabbit hole rapidly by hand matching every measurable characteristic of every component. You step into the realm of 2nd, 3rd, 4th order effects and beyond. More power to anyone willing to foot the bill for that level of effort. Absolutely support individual choice, whatever floats your boat. After 100 hours of use, everything will have changed anyway. Commentary from the perspective of performing worst case design analyses on far more complex things than audio amplifiers.