The best BFR model is 

but it has a few errors & came 20 years too late for the open source craze.

There's also a library for simulating orbits.

https://rebound.readthedocs.io/en/latest/

It's not that a realistic BFR model can't be created, it's that it would involve a lot of pain.  It's such a simple shape & existing models created in editors are so bad, the lion kingdom considered not using an editor, but it wouldn't be possible to nail all the engine plumbing without an editor. You should ideally be able to see the engines vectoring.

Lions gained a lot of experience on Maya, back in the day.  You created models by dropping in basic math functions or nurbs & editing parameters in tables.  Then it polygonized the nurbs for use in games.  Crazy people could drag & drop.  Every component in the model was listed in a directory tree.  It was easy to quickly dial in dimensions, numbers of faces, textures.  Modelling machines was easiest with text entry.  Sadly, Linux support was dropped.

Goog made history long ago when it acquired Sketchup & made it Adsense supported.   In 2012 when Adsense revenue proved insufficient, Goog sold it to Trimble who made it web based & charged money for some features again.

There's a very simple BFS model for sketchup.  Views spiked after the Falcon Heavy launch, but nobody cares anymore.

https://3dwarehouse.sketchup.com/model/19d8280a-4fec-44fb-8927-7e8a4ab8710c/SpaceX-2017-BFR-Spaceship

Ben Heck uses Fusion 360, which is also not for Linux.

Tried out FreeCAD, written entirely in Python.  It looks substantial & close to Maya, but then come the newbie programming errors & lack of documentation.  Doesn't anyone write software for more than a single economic boom?  The mane problem is synthesizing the wing.  It's a nasty combination of curves FreeCAD can't solve in a single pass.