Belgium
While there is no full overview of the Belgian police available, the Police Lethal Force and Accountability (2021, 3MB PDF) has a section on the policies and practices in Belgium associated with the use of lethal force.
See the Publications page for a 35min video presentation of the Police Lethal Force and Accountability associated with this report and analysis.
Kenya and South Africa
The 2021 report Toward a Lethal Force Monitor (2MB PDF) provides an analysis of the policies and practices in South Africa and Kenya, associated with the use of lethal force. See the Publications page, where there is also a 45min video presentation associated with this report.
On that same page you also find the The Use of Lethal Force by the Police in Kenya (2021, 2MB PDF) resp. The Use of Lethal Force by the Police in South Africa (2021, 2MB PDF) reports written by Ignacio Cano for the African Policing Civilian Oversight Forum (APCOF).