The HT app presented the firmware update right away upon launching, so now I know it can do the upgrade. The first time I updated the radio, I used the older “BTech Programmer” app.
The update promises some fixes around
ackin in-built APRS,- TNC stability
I discovered in the app the setting: Radio -> ID Settings -> 3 Checkboxes (ID, Location, Check) could be turned off to get to “none” to disable post-TX noises, which is “PTT Release” in the radio.
Those settings kept gettign synced from the app to the radio, so now they’re set the way I want it to stay. I could have also disabled “Synchronous Signal Settings” in the app, but the mismatch seems like it would have been confusing.