[hara]

Welcome!

First of all, in what direction is the fan blowing air?

By spec, your heatsink should have the air sucked from it instead of blowing.

If that's what going on then by moving the fan will in fact reduce the deadspot (since air sucked has a laminar flow) but don't ask me how much and if performance will vary.

If your fan is pushing instead of pulling (like any other hs) than by moving the fan backward, performance could decrease since the airflow in front of the fan is turbulent. Heatsinks work well with turbulent flow but moving the fan back will not only shrink the deadspot but also reduce the airflow through the heatsink.

What I suggest you experiment with is to get rid of the shroud and mount the fan the other way round (i.e. Blowing into). Some people reported better temps this way.