Using the function: "exportImg" as described in the Qlik help documentation always uses 96 dpi, therefore the Image resolution is highly limited.
https://help.qlik.com/en-US/sense-developer/April2020/Subsystems/APIs/Content/Sense_ClientAPIs/Capab...
Investigations have shown that this limitation could be removed with a single line of code, just by adding the dpi as parameter in the setting.