The Debian-Live approach also provides some good opportunities. First and foremost, the very easy remastering makes it efficient to run with no persistent store quite often. For instance, upon remastering, I just start without the store, and the image I run is union-mounted with the persistence file and copied&compressed. Then I have to boot something else to copy the new squashfs image in place, but that's all that has to be done outside the system.
Boot the new image without persistence, create a new persistence file.
For further adaptations, the new persistence file can be mounted in an instance run under kvm, programs can be added and settings tweaked for an eventual new remastering.
Storing the series of squashfs-compressed images, one can always go back in this process if needed.
Cisco Catalyst C9300-24UX-A 24 Port 10G/mGig UPOE Network Switch + NM-8X Module
$579.97
Cisco WS-C2960X-48FPD-L 48 V07 POE+ GE+2 10G SFP+, LAN BASE 740W w/ C2960X-Stack
$99.95
Cisco FPR1010-NGFW-K9 FirePOWER Security Appliance **CISCO EXCESS**
$339.00
Cisco Catalyst C9300-24UX-A 24 Port 10G/mGig Copper UPOE Network Switch
$549.00
Cisco C3850-NM-2-10G 2 Port Network Exp.Module for 3850
$28.99
CISCO SFP-10G-LR SFP TRANSCEIVER MODULE GBIC 10G 10GB SFP - 1 Year Warranty
$39.99
Genuine Cisco SFP-10G-SR Transceiver Module (10-2415-03)
$5.85
Cisco 2900 Series CISCO2901/K9 v06 Integrated Services Router
$39.99
Cisco Catalyst C9200-48P-E 48-Port Managed Gigabit Ethernet PoE+
$575.00
UNCLAIMED CISCO MERAKI MS120-24P-HW 24-PORT GIGABIT CLOUD MANAGED PoE SWITCH
$128.20