CIF/SVG input mappings with updates: can't assign an input variable in a component definition that is defined outside of it

To work with the new execution mode, I am replacing our input mappings from events to input variables. Here, I have encountered a new problem, see the example model below:

input bool On;

group def Lamp(alg bool ON):
  svgfile "Lamp.svg";
  svgin id "Button" do ON:= true;
end

Lamp1: Lamp(On);

Results in the error "Lamp1.ON is not an input variable". Likely due to the defined parameter ON as algebraic boolean. However, I cannot change that to input bool as it does not recognise "input" as a type.