Yes, and this should be stated frankly.
A ruby strengthens the Sun, regardless of what a person expects from it. If the Sun in a chart is already harsh, if it rules difficult areas of life or is in its fall, the strengthening provides not support, but pressure. This manifests itself in recognizable ways: irritability, the need to prove oneself, heightened self-esteem, tension in relationships with those in a higher position.
For the same reason, ruby is not combined with stones of planets hostile to the Sun—blue sapphire, diamond, and hessonite.
A Sun stone is not chosen just in case. Therefore, we always ask if a natal chart calculation is available and, if necessary, we help create one.