Personally, I wouldn’t bother wiping the asustor. There’s nothing wrong with OpenMediaVault, but it’s not any more straight forward than TrueNAS. If you’re looking for beginner simple, maybe something like HexOS or CasaOS would be more to your liking. But that makes me wonder about Proxmox for this setup. I love Proxmox and use it extensively at home and at work. It’s incredibly powerful and flexible, but it’s a lot less hand-holdy than TrueNAS. By all means give them all a try—thats the fun—but expect a learning curve before things really click.
I hear you and I’m all for diving in—breaking things is half the fun.
If you’re after something straightforward for NAS software, another thing to consider would be vanilla Debian with Cockpit and 45Drives’ excellent filesharing plug in. I like the combo quite a bit.
Enjoy the journey!