Blender runs on my daedalus with LXDE and it is not asking for (non-existing) libraries, like libavformat.so.58.
Maybe an apt dist-upgrade was missing during the last upgrade?

$ apt list --installed | grep -e libavf -e blender -e libsws

blender-data/stable,stable,now 3.4.1+dfsg-2 all [installed,automatic]
blender/stable,now 3.4.1+dfsg-2+b1 amd64 [installed]
libavfilter8/stable,stable-security,now 7:5.1.4-0+deb12u1 amd64 [installed,automatic]
libavformat-dev/stable,stable-security,now 7:5.1.4-0+deb12u1 amd64 [installed,automatic]
libavformat59/stable,stable-security,now 7:5.1.4-0+deb12u1 amd64 [installed,automatic]
libswscale-dev/stable,stable-security,now 7:5.1.4-0+deb12u1 amd64 [installed,automatic]
libswscale6/stable,stable-security,now 7:5.1.4-0+deb12u1 amd64 [installed,automatic]

My "mother of all apt pins" is

$ cat /etc/apt/preferences.d/systemd.pref 
# not anymore #  Package: systemd 
Package: *systemd*:*
Pin: release *
Pin-Priority: -1

Not sure about the exact syntax, lets say it works so far.
Cases: On debian 12/13 to prevent re-installation of some systemd-stuff. On excalibur, just to be sure. And some "purge systemd in debian"-experiments as a preparation for a controlled devuan-migration.

Variants: On machines with multiarch, it's sometimes "Package: systemd:*"
Compared to @nixer's post: No wild card in the package name. Just mentioning, no clue about the consequences.
Edit: Not good enough anymore without wild cards
Edit2: Never realized the possibility to have multiple package names in one line, which will simplify some .*pref  files
Edit2: Stumbled upon the package "systemd-dev"

The title is "Beowuf to Chimaera", but you mean to Daedalus, right?
Otherwise, Chimaera has wicd.

I do not know Peppermint OS.
Are the deb-multimedia.org keys installed?
Did you copy an old sources.list, still pointing to debian-multimedia.org?

@#1
In case the partition is mounted read-only (ro):
Altering the permissiion of the directory to read-write is not enough. The partition must be re-mounted read-write (rw) as well.

First check the output of mount to see whether this applies at all. (sticking to /dev/sdb1 as example)

$ mount
$ sudo mount -o remount,rw /dev/sdb1

Open question to answer is still: Why was the partiton mounted read-only at all?
Re-mounting the partition rw manually is curing a sympotom - if the real reason allows this at all.

In short: There is no way around UEFI boot for a gpt disk.

gpt disk and non-uefi boot are mutally exclusive. This can not boot by design - it's not an error.

gpt partion table -> UEFI boot
mbr partiion table -> BIOS boot

Modern x86 PC's are all UEFI. Addionally they have a BIOS emulation, which allows them to boot mbr disks.
An "UEFI emulated BIOS" counts as BIOS.

In a terminal: Both commands will extract the archive's content in the current directory

$ 7z /path/to/arch.zip 
$ unzip /path/to/arch.zip

Multitasking in compression is a trick that zst does.
I don't use it very often, since the command-line switches and defaults are sick, but (de-)compression works nicely.

I would check that sysvinit is installed (and running if booted):

apt list --installed | grep sysvinit-core
apt list --installed | grep systemd

Obviously, there should be sysvinit-core and no systemd. Then:

apt update
apt -s upgrade
apt upgrade
apt -s dist-upgrade
apt dist-upgrade

usually did it (without forcing or expicit de-installs).
The apt -s lines are optional. They do a simulation to spot problems. It might be tricky to solve dependencies in an interrupted migration.

Some programs will be de-installed during migration, so there is stuff to re-install.
And optional clean-up at the end: apt clean and/or apt autoremove

--
PS: Booted installtion with sysvinit:

$ ps ax | head -2
  PID TTY      STAT   TIME COMMAND
    1 ?        Ss     0:00 init [2]

In case of systemd: PID 1 is "/sbin/init"

Do you have a specific need for openjdk-8?
Maybe a newer version is already installed.

apt list --installed | grep openjdk

# apt dist-upgrade

works too in such cases.

It looks like a firefox (variant), which is good form my point of view.
What is midoris selling point?