When cooking a pork loin roast in a slow cooker, the cooking time depends on the size and thickness of the roast, as well as the setting (high or low) you are using. Since you mentioned using high heat, I'll provide an estimate based on that.
Generally, for a 2-pound pork loin roast on high heat, it will take approximately 3 to 4 hours to cook thoroughly. However, slow cookers can vary in their heating levels, so it's essential to check the internal temperature of the pork loin to ensure it's fully cooked.
To be safe, use a meat thermometer to check the internal temperature of the thickest part of the roast. Pork is considered safe to eat when it reaches an internal temperature of 145°F (63°C). Keep in mind that the carryover cooking (residual heat) will continue to raise the temperature by a few degrees after you remove it from the slow cooker, so you can take it out when it reaches around 140°F (60°C).
Additionally, the vegetables in the slow cooker will likely be fully cooked and tender after 3 to 4 hours as well, so the dish should be ready to enjoy!