Best way to manage multiple OS installations (backup, flash)

[3x5co]

I know there are a number of threads addressing issues similar to this, but this request is specific: 

I have spent a lot of time with Mobian, and gotten it as close to my liking as possible, but I am not ready to use it as a daily driver. I would like to back up my Mobian installation and then maybe try UbPorts again. If I don't find it useable I will switch to Graphene for now.

But, in a couple months, maybe I will boot my Mobian installation again, run some updates, and see how it handles. Of course, I don't want to lose my GrapheneOS installation in case I need to switch back. 

So how to manage multiple installations? Should I just use dd?

[The3DmaN]

I know there are a number of threads addressing issues similar to this, but this request is specific: 

I have spent a lot of time with Mobian, and gotten it as close to my liking as possible, but I am not ready to use it as a daily driver. I would like to back up my Mobian installation and then maybe try UbPorts again. If I don't find it useable I will switch to Graphene for now.

But, in a couple months, maybe I will boot my Mobian installation again, run some updates, and see how it handles. Of course, I don't want to lose my GrapheneOS installation in case I need to switch back. 

So how to manage multiple installations? Should I just use dd?

You could make a backup of the entire sd card (or EMMC with jumpdrive) to your computer. Gnome Disks works well for this. Depending on the size of your sd, this may not be ideal and would take a long time. You could also have one OS on the EMMC (secondary) and one on the sdcard (primary) (this is what I do), then if you ever want to use the secondary OS you just power off, pull the sd out and reboot. Or the 3rd option use multiple sd cards and install one OS on each card and swap them out as needed.

[C0ffeeFreak]

I know there are a number of threads addressing issues similar to this, but this request is specific: 

I have spent a lot of time with Mobian, and gotten it as close to my liking as possible, but I am not ready to use it as a daily driver. I would like to back up my Mobian installation and then maybe try UbPorts again. If I don't find it useable I will switch to Graphene for now.

But, in a couple months, maybe I will boot my Mobian installation again, run some updates, and see how it handles. Of course, I don't want to lose my GrapheneOS installation in case I need to switch back. 

So how to manage multiple installations? Should I just use dd?

Balena etcher, probably the program you are using to make your drives has an option to clone a drive. I haven't tried it yet on the Pine phone, but couldn't you clone the EMMC to a SD card and back again?