@oschulz I have no idea how I missed your reply. Sorry for that!

Regarding `SpatialVector`

, I initially wanted to implement it as a `StaticArray`

, but I remember there were lots of bugs at the time, and I wanted it to behave as a scalar with regards to broadcasting. Additionally, the performance of `LorentzVector`

/`SpatialVector`

is (was?) in my experience much more deterministic than `StaticArrays`

(I played a bit with Pauli/Dirac matrices a few months ago, implemented using `SMatrix`

, and I hit some weird performance issues).

So, basically, I chose the simplest and most reliable solution for my needs at the time, but I might reevaluate it now that `StaticArray`

is hopefully more stable. I would definitely like to have the free math and composability