I have a used(new to me) N900 coming in a few days.
This means moving everything off of my no-SIM-detected phone.
My current plan is to:
1-flash arriving N900 to factory
2-install thumb-CSSU repo
3-install QR code reader(and quickresponse plugin on my laptop browser) and get all new repos loaded into N900's package manager
4-install KP
5-install backupmenu
6-load root and opt backups from old phone using backupmenu and the SD card
7-hope phone boots into my Maemo setup, else repeat steps from #1

Is there a better way to do this or is this the fastest?
There was once a few images which were updated and did not require several long bootstrap steps potentially wasting a few hours if you don't pay attention.

OK, I install
http://maemo.gilababy.com/apt-mirror/repo/ovi.install
http://maemo.gilababy.com/apt-mirror/repo/ssu.install
http://maemo.gilababy.com/apt-mirror/repo/apps.install
and
http://maemo.merlin1991.at/cssu/comm...mantle.install

do the CSSU thumb install and click enabler
install backupmenu and KP53

third time I did something wrong, bootlooping and flashing fresh
I remember there being a way to build a flashable image form a backupmenu archive and I think a kernel image

With the rescue os it is possible to backup and restore the rootfs.
Did you tried that?

0xFFFF have ability to create rootfs+kernel image
BTW maybe cssu thumb installer have some protections but if not then you are doing it wrong: you can't install thumb and then kp53 which support thumb instructions.
Is CSSU testing shouldn't be installed before thumb?

I skipped the CSSU and just got enough repos set up
to install KP53 and backupmenu,
reboot,
backupmenu install / and /opt archives,
move over MyDOcs files
and done
Phone cloned

Since the thread's title doesn't specifically mention backupmenu... is there a way to do this *without* backupmenu ?

My main N900 has backupmenu installed, yet it doesn't launch (stalls at udev, 1, 2).
Backupmenu launches fine on my second N900.

The only easy way is backupmenu.
Anyway I'm pretty sure it is possible to do this with rescueOS (opt) + 0xfff (rootfs + kernel) but it would be not trivial and for sure time consuming.