Exploration and optimization in the large parameter spaces of disruption mitigation is currently only feasible with reduced dimensionality numerical models, such as DREAM. Higher dimensional processes - for instance vertical displacement events or the $E\times B$-drift of newly ablated material from disruption mitigation pellets - are not intrinsically captured by these tools, but they may be accounted for through effective models. In this contribution we present semi-analytical models for ablation cloud drifts and runaway electron losses due to scrape-off during a vertical displacement event, which have been recently implemented in the DREAM code, to increase its predictive power. The ablation cloud drift model [1] is based on an analytical solution of the equation of motion for a plasmoid with a uniform drift velocity, combined with a simplified model for the cloud expansion parallel to the magnetic field. The solution accounts for both the Alfvén and Ohmic currents that short-circuit the charge separation responsible for the $E\times B$-drift. The scrape-off runaway electron losses are modeled utilizing that the poloidal magnetic flux between the last closed flux surface and the conducting wall remains approximately constant on the time scale of the current quench, as borne out in ITER simulations with JOREK [2]. In this presentation, we describe these implementations and discuss their implications for runaway electron avoidance by shattered pellet injection in ITER. [1] O. Vallhagen *et al*, J. Plasma Phys. **89** 905890306 (2023).\ [2] C. Wang *et al*, submitted to Nuclear Fusion (2024).