>> I have gone through a few YouTube clips telling us to back up the micro SD data card that has the ASIAIR pro OS..
>> is this necessary for the new Pro version?
Absolutely! Don't even attempt to apply power to the ASIAIR after opening the box. Back up the microSD card first. If you have more than one ASIAIR/pro, be sure to back all of them up, since that all have different license files.
The reason is if you happen to forget to soft power down the Raspberry PI and the ASIAIR is in the process of accessing the SD card, the card could be rendered useless. There are also people who physically crack their microSD while inserting or removing it. The pro model of the ASIAIR is especially prone to this because ZWO's metal case has a deeper ledge under the microSD card than the original plastic box from Raspberry Pi. I recommend using a tweezer, or temporarily stick a Gaffer tape to the part of the microSD that is visible, and carefully pull on the tape to extract the card -- do not, under any circumstance, apply any pressure that can cause the card to bend or crack.
Your license file resides on the card.
In case you lose your SD card for some reason, the easiest thing to do is to restore from a backup copy (the license file is included in the backup). It takes about 20 minutes to restore the 32 GB image, and you are done.
If you are on a decent computer, backing up takes less time (of the order of 5 minutes) since it is faster to read from the card than to write to the card.
If you don't have a backup copy of the microSD image, you will need to find a friend who you can copy from, or download a 32 GB image that ZWO has placed on a Google server. Depending on your internet service, this can take a while.
Even if you now have a good microSD image from the Google server or your buddy, you will still need to add/replace the license file on the new microSD card with your own license file. If you also haven't squirreled away your license file, then you need to take a screen image of the startup window that includes your ASIAIR serial number (it has part of the ARM processor ID). Email that to ZWO and wait for them to send you some QR image that contains the license. It is a manual process, so the wait time varies.
Each Raspberry Pi has a unique processor ID burned into the ARM chip. ZWO uses that, together with encryption, to create a unique license that works only with your copy of the ASIAIR hardware.
Might as well bite the bullet and do a backup now. As the TV commercial says, "Pay me now, or pay me (much more) later."
Chen
