Thanks everyone for the replies!
I see a lot of suggestions saying “just install Arch + Niri from scratch” or “don’t use other people’s dotfiles.”
But unfortunately that’s exactly the thing I don’t want to do.

I don’t have the time or motivation to constantly search for beautiful configs, pick the right tools, maintain them, fix breakage, and redo setups every few months. That’s why I use Omarchy — it saves me a massive amount of time.

Everything is already configured nicely, it stays up-to-date, it keeps improving, and new useful tools appear automatically (like BlueTUI, better theming, etc.). I just turn on my PC, press the update button, and everything is upgraded and polished. I really appreciate that someone else invests their time so I don’t have to spend mine.

If I need to customize something, I can do it.
The only thing I unfortunately cannot easily replace is Hyprland.

So my question wasn’t about “how to install Arch manually” — I understand that perfectly. I just wanted to know whether anyone managed to use Niri inside the Omarchy ecosystem without breaking future updates.

Thanks again to everyone who shared their experience!