aim to avoid the transient into this regime by numerically cutting back all violations of condition (\[eq:force\_free\_dominance\]) [e.g. @Palenzuela2010; @Paschalidis2013; @Carrasco2016] or include a suitable Ohm’s law [e.g. @Komissarov2004; @Spitkovsky2006; @Alic2012; @Parfrey2017] in order to minimise these violations during a transient phase. Figure \[fig:energy\_dissipation\_channels\] shows the breakdown of condition (\[eq:force\_free\_dominance\]) during the simulation and hints towards the aforementioned dissipative processes. We refer to appendix \[sec:ff\_breakdown\] as well as, for example, @Lyutikov2003 for further details on the necessary constraint preservation and limitations of the highly magnetised regime (such as the lack of physical reconnection). We will give a thorough review of the procedures employed in our code in a subsequent technical paper.

Twisted magnetar magnetosphere models {#sec:twisted_models}
=====================================

Magnetospheres {#sec:initial_data}
--------------

      Quantity                   Nongeometrised unit                            Conversion factor
  ----------------- ---------------------------------------------- -------------------------------------------
        Mass                              M                                         $M_\odot$
       Length                             L                                    $M_\odot G c^{-2}$
        Time                              T                                    $M_\odot G c^{-3}$
   Electric charge   $\text{L}^{3/2}\text{M}^{1/2}\text{T}^{-1}$         $(4\pi)^{-1/2}M_\odot G^{1/2}$
   Electric field    $\text{L}^{-1/2}\text{M}^{1/2}\text{T}^{-1}$   $(4\pi)^{1/2}M_\odot^{-1} G^{-3/2}c^{4}$
   Magnetic field    $\text{L}^{-1/2}\text{M}^{1/2}\text{T}^{-1}$   $(4\pi)^{1/2}M_\odot^{-1} G^{-3/2}c^{4}$
   Current density   $\text{L}^{-1/2}\text{M}^{1/2}\text{T}^{-2}$   $(4\pi)^{-1/2}M_\odot^{-2} G^{-5/2}c^{7}$
     (EM) Energy        $\text{L}^{2}\text{M}\:\text{T}^{-2}$                   $ M_\odot\:c^{2}$
     (EM) Stress        $\text{L}^{-1}\text{M}\:\text{T}^{-2}$             $ M_\odot^{-2} G^{-3}c^{8}$

  : Conversion table between code output in Heaviside-Lorentz *geometrised* units ($M_\odot=G=c=1$) and *non-geometrised* Gaussian units. In order to transform the respective quantities from code quantities to the *non-geometrised* 