I am not sure this is bug or issue, but I needed this slider 0.3<0.5<0.8 for optimization purposes.
Typing “0.3<0.5<0.8” does the job, but doubleclicking on it, gives false information about range (0.3-1.3), and also if i change anything on that screen it changes slider accordingly and it is not possible any more to have range less then 1.0.
Any way i have solved my need by making slider 3<5<8 and dividing by 10.
Just reporting if this is common issue (rhino 5 / grasshopper on Windows).
All the best!