At the AllieExpress price, using those hard spring on the official Lego soft-spring 2909c03 could work. The springs at 2 Euros a piece is pretty steep.
Could not find them at McMaster-Carr nor in a quick Google search.
Found them for sale here:
https://toom.de/p/druckfeder-federstahl-99-x-43-x-09-mm-1-stueck/1621352