the most stable way to read the line status for all lines should be to use the Chunk Line Status All.
Here you are able to collect information from every frame line what the current line status of all line was, after receiving a frame.
Line Status All is a 8 bit value that contains a boolean for each line. For more information on that have a look here: https://forum.commonvisionblox.com/t/working-with-3d-cameras-of-automation-technology-in-cvb/532/19
Std::LineStatusAll can also be tracked instead of each individual line. this should result in a better performance.
In case you want to use some kind of callback there are GEV Events available but they do not support the change of a line status. As some kind of workarround you might be able to trigger one of the available events using a line as event trigger and check for the GEV Event from the software side. This will probably not provide you with all desired information, but I think it’s worth mentioning.