Cross-posting this from Reddit as I know a few of us have the Boss Audio HU installed and I was able to apply the FW update successfully to my BE7ACP-FT.

I wanted to share a fix for Boss Audio Systems CarPlay stereo head units that's helped me resolve an annoying issue causing an echo during calls in CarPlay. This info was not easy for me to find online, so I figured this might be a good resource for others in the future.

My unit is BE7ACP - the cheapest aftermarket CarPlay at the time at BestBuy

First, you can find and locate your firmware update on their website using this link: https://bossaudio.typeform.com/bossfirmware

Then you can follow these instructions that were emailed to me by their support team: STEP 1 Preparing your USB Drive

1. USB Drive should be 32GB or less and formatted FAT32 before continuing with the update.
   
2. Download and copy the Update File to a BLANK formatted USB Drive.
   
3. Unzip/Uncompress the firmware update (zip) file (XXXXX-builtindsp-) into the root directory of a blank, formatted USB Drive.
   

STEP 2 Beginning the Update

Precaution: When updating the head unit, make certain that the POWER is not interrupted while the update is in progress. If POWER is lost or interrupted the unit may become inoperable.

1. Turn OFF power of the head unit via the ignition key for 30 seconds.
   
2. Remove any connected USB devices from the radio.
   
3. Insert the USB Drive with above copied files to the CarPlay / Android Auto USB port.0
   
4. Power ON the head unit via the key and/or POWER button if necessary.
   
5. Allow a moment for the USB to load. Select “Settings” icon, at the bottom of settings page select the “ABOUT” tab (take a photo of the ABOUT screen for reference, the SOC portion should change/update when you’re done.) Scroll to the bottom of the “ABOUT” screen up beneath about you will have the option to select “UPDATE”.
   
6. The unit may blank out for few minutes while the update process is being started.7. When the progress bar has stopped progressing and the (Model number) restarts (about 5 minutes), immediately remove the USB Drive and TURN OFF the IGNITION KEY and restart the UNIT normally.
   

STEP 3 Confirm the Software Update

1. Select SETTINGS > ABOUT
   
2. Check the ABOUT screen again, this time the SOC version installed should have changed. This is how you verify that the update worked properly.