Is it possible to use systemd-sysupdate to update a machinectl container from inside?

I'm using machinectl to run self-contained sets of services on some servers and appliances. I'm packaging my application to fit within the machinectl image so that it runs mostly independently of the host system, which I hope to be agnostic of (for hardware support and simplicity). I'm looking for a method to setup an auto-update system for my application, and systemd-sysupdate seems the natural component to reach for.

Reading the sysupdate documentation, I see two scenarios elaborated:

1. sysupdate updates the entire host system. It fetches updates and sets it up in another partition, with the relevant bootloader setup. This option seems unideal for me, as I wish to avoid touching the host system as much as possible, and I don't believe I can apply this method to only my machinectl container, as the container has its own root tree but no separate filesystem/block device.

2. sysupdate updates the container from the host system. It fetches updates and swaps out the container root tree from the host. This option seems more feasible, but still unideal, as I have to set up sysupdate on the host system rather than from inside my (persistent) guest container. (On another note, I'm also not entirely certain how it works when the tree gets swapped; if the update happens and the tree is swapped while the container is running, wouldn't things break? sysupdate must have some mechanisms in place to prevent this?)

Since on a machinectl container, I possess systemd inside my container as well, is it possible to swap out the container's tree from inside the guest container itself?