print(renoise.song().tracks[1].devices[1].parameters[1].value_quantum)
I assume this should return the value that is used by the interface when pressing the </> increment/decrement buttons next to a slider (ie similar to the step setting for user created sliders), that could be used to nudge parameters appropriately from scripts.
But it seems this value is always zero, no matter for what parameter.
No, this is only ~= 0 for enum, integer or boolean alike parameters. Non continuous parameter values.
Ah ok, so for discrete parameters this will always be 1, while for floats it will be 0, right? Or is there some case where it can be something other than these?
Not necessarily. When the value is a normalized value (e.g. in plugins it always will be) then it may be < 1 too for integer, enum alike values too.
So you need to apply it on the parameter value’s range.
step would have been a better name for this.