The humidity in the house, not the hot air, affects everything. Dry air will shrink the furniture and wood flooring, where warm humid air will not. When furniture shrinks from a dry environment, it often breaks the glue joints loose. So even when the humidity is brought back to normal, the damage is done and the furniture will have to be re-glued to be strong again. Wood flooring, when in a shrunken state, will fill the gaps with dirt and crud so it will not come completely back together when the humidity comes back to normal.
Your possessions aren’t the only things affected by dry air. Many health problems are inflamed by dry air. Your skin and sinus cavities are equally susceptible to lack of humidity. Plus you can keep the thermostat a little lower and still maintain the same level of comfort with a little more humidity.
Another note is moist air will equalize the same all over any floor of your house. This makes it difficult to have one room with more humidity than another does. If your humidistat (available for around $10) is reading under 25% relative humidity, you should either get a humidifier or fix the old one. Thirty-five to 40% is an acceptable amount of humidity that will help prevent the wood in your house from shrinking, the noses from bleeding, the static electricity from shocking everyone.
Air deflectors come in a variety of sizes and shapes so it is easy to direct the air so it circulates around a room. The goal here is to stir the air in a room so it mixes throughout the area. Try to send the air the long way towards the cold air return. This will help even out the warmth throughout the room. See Floor air-deflectors for effective heating and cooling for more.
It is good to prevent air from blowing directly on furniture and drapes. They tend to collect dust from the furnace if directly in the path. They also hinder the flow of air from mixing in to the room because the obstruction slowed the velocity of the air.
As to specialized air deflectors, we just finished some 50-inch deflectors for a local church. We made them out of Plexiglas and used magnetic tape to hold them to the registers. Only your creativity and your budget limit the design and size.