I’ve gone the TrueNAS SCALE route myself, with TN running on bare metal. All my containers/apps are set up through it, and I’ve also spun up Windows and Linux VMs without major issues, including GPU and USB passthrough.

I do enjoy the security it gives me, will all my apps being versioned/snapshotted regularly and before every update, as well as the rest of my data. Since TN is only using ZFS and not something like MergerFS (which I believe is used by Unraid), the upgrade path is a bit mote restricted. So you should definitely look into your options up-front. For example, you won’t be able to expand a vdev (virtual ZFS disk) later on, you’ll have to create a new one. And you can only use equivalent vdevs to form pools. That means if you start with 3 drives in a vdev for your main storage pool, you can only expand that pool by adding anothet 3 drives with the same capacity as a secons vdev. So make sure you can stomach these costs, or go for fewer and cheaper drives, with a large case.

As for apps, you can set up docker apps easily, and there are a large number of officially or community-maintained apps, where any breaking changes and migrations are handled for you, so updating is a breeze. But you don’t have a much flexibility as with a custom setup. TN has been becoming more generic in that regard though, switching from k3s to regular docker, so you could probably play around with stuff via the CLI without major issues.

Oh and one more thing: you should probably use a separate, dedicated device for Home Assistant. Use a Raspberry Pi or one of their official boards, and you’ll have better support, more features, redundancy, and can still create backups on your NAS via SMB.
Such a second device that is also connected via Tailscale doesn’t hurt either, just in case.