Interesting - manually created Control Points (CPs) ‘a few pixels off’ sounds like RC should be able to take the assistance offered, however imperfect.
But come to think, if RC gives those rather approximate CPs the same status as its automatically generated Tie Points (TPs), that’s giving authority to some wildly error-full points, by TP standards. Especially if those CPs are given a high weighting number.
When Mean and Median reprojection error are typically in the 0.3 to 0.5 pixel range, and Max Reprojection error is set to 1 or 2 pixels, then CPs ‘a few pixels off’ are seriously error-full. Looks like CPs need to be zoomed-in enough to be placed with exact 1-pixel accuracy - and even that is way over the 0.3 to 0.5 pixel range.
Furthermore, if those CPs (if they’re in fact not really ‘points’ but artificial 2D Features) are projected (just as normal automatically detected 2D Features) to 3D near-intersection to create an artificial TP, which is then REprojected to the 2D picture planes where REprojection error is measured …
… maybe a geometric multiplier something like 1/sin30 is applied, so the REprojected error resulting from ‘a few pixels’ CP-placement error is actually twice (or more) greater.
This all would make reliance on CPs into a dangerous process, inherently injecting lots of error (rather than, you’d have thought, confident human-visual accuracy) into the system. Especially if there’s lots of CPs and/or they’re given high weighting.
Maybe CPs just can’t be placed with anything like high enough accuracy, compared to most TPs.