Hello, I have problem with script claimit.py, respective with adding multiple values of one statement.

Typical problem is P31. 
In wikidata is often 
P31=Q123
P31=Q456

and I want to add some other. I tested various combination of -exist:ptqs, but always there is some item to which is not added new value or added duplicate

In https://www.wikidata.org/wiki/Q10854900

my idea was: 
P31=Q811534 (1x)
P31= ... various trees 

But script added (-exists:ptq) in every run one instance of Q811534 and one instace of certain taxon. After few runs script says that P31 already exists and does not add new taxons
(this item maybe should be solved in different way, but problem is not only in this item and this property)

Is it problem in script or only incorrect combination of letters? 

JAnD