How much front clearance do you find necessary?

I just had my p61A installed. It's a corner installation, and the way the room is currently layed out, we have the output of the blower facing the back of one of our couches, which is about 3' away. The height of the blower output is about an inch higher than the back of the couch. I had hoped that the hot air on a medium-ish blower setting would rise enough over that distance to where I wouldn't be impeding flow too much with the couch. It is not yet clear that this is the case.

I have some experimenting to do to see how the overall reach of the stove is affected if I move the couch out of the way... but I was wondering if anyone had a rule of thumb or some experiences of their own to help set my expectations.

The blower on my stove has a quiet and normal setting (low/high). It's set to low on default and for the heck of it I bumped it up and now consistently get the other side of the house closer to the stove set temperature. If the hot air is crashing against the sofa, some of that heat is being absorbed by the sofa instead of being pushed out into your living space.

As a general rule of thumb, the more you can keep open the area in front of the stove, the better the heat distribution in the area.

If you care much about your couch it may not be wise to have it that close.