Question about Offline Updates and external storage persistence

I have balenaOS is installed on a primary SSD.
I also have a standard SATA 3.5 HDD connected to my board.
This HDD contains large media files that will get consumed by other containers. Data on it should persist in case of any update whether it be host OS update, application update or offline update.

From the information I gathered, I’d have to this:

So far, this will survive host OS and application updates right?
But what I’m confused about is Offline Update and specifically this quote from the documentation:

These external storage devices are not part of the update process, so data on them would be left intact, as long as they are temporarily disconnected during the update process.

And it also says:

If a device isn’t local, you can just ship the SD card or USB stick/drive to a remote location and let someone there run the update by simply inserting it into the device and booting.

Do I absolutely have to disconnect the HDD first? If I don’t, will the offline update erase my HDD?
If I ship a USB containing offline updates, do I have to tell that someone at a remote location to disconnect the HDD first specifically?

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Hi, thanks for your message. Whether the external drive needs to be removed will depend on the provisioning method of the device type in question. Non-flasher devices, those that do not require to boot from an external drive to detect and program an internal one, should not try to access external drives. However, flasher device types will program into the first detected device from a static list, so the installation might use the external drive you want to preserver, depending on which order the kernel detects the drives.
What type of device types are you using?