Late to the game, new DC-ZS200 owner. Coming from Sony DSC-HX20V, HX30V, HX50V & HX80V - which all have been great. Added the ZS200 to the collection for the 1" sensor, 15x Zoom & 4K.
My ZS200 was previously owned with firmware version1.0. I was able to access the service mode and the "recording limit hack" was successful from this version.
While the mode was still active, I have installed the latest firmware V1.2 and the camera continued to stay in the "hacked " mode after the update.
Firmware revisions show:
Date/Version: Nov. 19, 2019 Ver.1.2 [Exposure Comp. Disp. Setting] has been added to the [Custom] menu.
Date/Version: Dec. 20, 2018 Ver.1.1 [Fixed bug in contrast adjustment of monitor.]
https://av.jpn.support.panasonic.com/support/global/cs/dsc/download/TZ200_TZ202_TZ220_ZS200_ZS220/index.html