A 52-year-old man with long-standing COPD is being assessed in clinic. He is on dual long-acting bronchodilator therapy and uses salbutamol as needed. He has had two moderate exacerbations requiring oral steroids and antibiotics in the past year. His resting PaO₂ on room air is 7.0 kPa (52 mmHg), PaCO₂ 5.6 kPa, and oxygen saturation is 88% at rest, confirmed on two occasions three weeks apart while stable. What is the most appropriate management regarding oxygen therapy?