The force needed to set the(rear)trigger depends on the tension of the main spring and (more important) on the lever transmission.
The geometry of the commercial Mauser DST for example is a bit more optimized and therefore easier to handle.
You should have in mind that the tension of the mainspring is responsible for the power of the protrusion to make the mechanism working.
Changing the geometry is impossible and weakening the spring, what can be done, may result in easier setting but destroying the function.
So I would recommend : hands off !