The detection range of IR-LOCK/MarkOne with the default lens and beacon is ~15+ meters.
The detection range can be increased by (1) choosing a different lens and/or (2) using a larger MarkOne Beacon. However, there are some more details to consider.
(1) If you select a lens with a more narrow FOV, then the detection range will increase. However, the FOV decreases. And you will need to modify the lens model.
(2) We develop and sell larger MarkOne beacons for commercial drone projects. This typically requires a minimum order of ~$2,500.
Also, with regards to Precision Loiter, the loiter accuracy will tend to decrease as the altitude increases. This is not an issue with Precision Landing, because the accuracy improves as the copter approaches the target on the ground (and the high-altitude accuracy is not a major concern).