Suggar Daddy (Pimp edition 1m93) mounting point

Hi,

I am the owner of a pair of mentioned skis for now 2 seasons, but I dont like the position of the bindings on the skis.
When I purchases them, there was only one mark on the skis for the drilling and so it was how the bindings were positioned.

Although they are twin-tip skis, they are primarily for me fat powder skis (I never ride switch/fakie and dont do air at all).
The nose of the skis sinks on powder days. I clearly feel that too much weight is on the first half or so of the skis and I dont think that it is due to poor technique.

So I want to move the bindings a little bit backwards....but I dont really know by how much??

Would anyone have advise, recommendations or even know these skis and what position he would recommend for my usage?

What is the rule of thumbs to determine the mounting point for powder skis (and skis in general)?:confused:

Thanks in advance! :)