rescue image with ext4magic or extundelete

Some rescue operations and similar need to be done with the the drive or volume unmounted. Previously I have downloaded an .iso of GParted which I put on a USB stick and booted up from it into a basic gui from which it was possible to rearrange the partitions on the disk. Now I just deleted a single file I've been working on for days with rm (I know..) and need to really try to get it back. ext4magic should be able to do it, I have the command ready to go. extundelete maybe but that one is unmaintained. I just put my debian-11.3.0-amd64-DVD-1.iso onto the USB from a dd command and booted from it. There was a 'rescue mode' option. That provided a semi-useless terminal with almost no commands or otherwise it allowed the root partition of the PC to be brought to life in a terminal. So I did that but the partition with the file I wanted to recover being /home was also mounted but I needed it unmounted. There are a few rescue things out there such as - https://www.supergrubdisk.org/ https://www.system-rescue.org/ ...which don't look like they have it. I just tested https://www.finnix.org/ - dd'd it to the USB and booted it into its terminal. It had a lot of commands but none to recover ext4 Does anyone know where can I find a bootable CD .iso image to put on the USB-stick which will boot into some kind of live system, not insist on partitioning the drive or installing itself, and have available the command ext4magic or otherwise extundelete ?