Yes, for those that find the ZS6 has too much treble, then somehow disabling or removing 1 BA is my personal preference.
You could do it many different ways - plugging 1 of the BAs with laser bond/blue tac/beeswax/clay/epoxy, ripping 1 out with pliers (hopefully not damaging the other BA), etc.
However, since I made that post other methods have come out by others, mainly manipulation using resistors - directly soldering, using an impedance adapter, or using a $3 3rd party in-line volume control adapter (which are simply adjustable resistors ie rheostat/potentiometer). The advantages of the volume control is its 1) low cost 2) fully reversible 3) infintely adjustable so you can tailor the treble to your liking.
If you search for content by
@Otto Motor, he beautifully details how to use one on the ZS6 (and I think he even includes graphs showing the effect on treble).
There are other methods of tuning the ZS6 as well, but they are much more advanced for the average Joe.