Is it true to say that every matrix $A\in M_n(\mathbb{R})$ is similar (conjugate) to a matrix $B=(b_{ij})$ with $b_{ij}=-b_{ji}$ for all $i\neq j$?(With some abuse of terminology,a matrix $B$ with this property is called "Semi antisymmetric").
If the answer to the above question is affirmative, then the answer to the following question is affirmative too:
https://mathoverflow.net/questions/279879/is-a-linear-vector-field-geodesible
The reason is mentioned in Remark $2$ of the latter post.