Climbing out of YHOT with terrain slightly rising at a density altitude of about 7,000', hence climb performance was vastly different from sea level ops, brought to the front of mind my question about leaning as you climb because I never have done it.
What speed were you flying? Flying too fast will also greatly decrease climb performance. If climb performance was an issue, you probably should be targeting around 70-75 KIAS, or even slower e.g. 65 for best angle to clear terrain.