EDIT: I missed that you don't want NAT. The device below, should be able to run in that mode, but I've only done so with IPv6.

Yes, and if you want auto-updates, check out the Turris Omnia: https://www.turris.com/en/omnia/overview/

It's the best wireless router I've ever owned.

Pros:

  - nice simple GUI for your typical stuff
  - advanced GUI (that runs in parallel) for advanced stuff
  - auto-updates with timely patches
  - open source (inc. their additions) -- based on openwrt
  - developed by a reputable non-profit that's been around since the 90s (CZ.NIC)

Cons:

  - a little pricey
  - current model is a few years old, so it's not the fastest option out there
  - the current model doesn't support 802.11ax

To turn off the firewall, you just uncheck a box. I think all the other advanced stuff was opt-in.