There are many of us who like to play around with the operating system on their phones but of course whenever we do this there is a risk that it may all go pear shaped and we end up with a non-functional phone. This is why every single time Ausdroid recommends that a backup using your custom recovery be performed before attempting to edit or replace any part of the system partition.
The problem with performing backups is that a backup can take up a lot of your on-board storage. The backup is basically a disc image so that you can restore it back to the way it was before without any loss of data etc. The backups are large — the backup of a standard Pixel XL is over 13gb (assuming you have a decent amount of data on your phone like I do) which is why I purchased the 128gb variety. Even with 128gb, perform a couple of these and you quickly run out of space.
Coming soon beginning with version 3.1.0 of TWRP will be the ability to make full backups straight to your computer using the ADB backup command line tool. Using this command you can actually create backups without having root access or a custom recovery but TWRP will be making this process a lot more automated than performing the command line instructions yourself.
Within TWRP, when performing the nandroid backup will be options that will allow you to automatically save the backup to your PC instead of the on-board storage of the phone/tablet. This will be very handy for those who like to perform backups regularly or who have a limited amount of space on their phone.
At this stage the time frame of the new release is unknown. It will be ready when it is ready, remembering that these developers are not paid for their work (aside from the very occasional and small donation). Is this something you will use? Will you backup your phone more often when this is available?