The custom LLD macro usage is quite inefficient.

In the case of LLD macros defined in LLD rule with jsonpaths server will first parse lld row into json object, perform jsonpath query and then free the object. This could be optimized by caching the object associated to LLD row. Even further - the LLD data could be parsed into object in beginning and this json object tree could be used directly.

Adding caching might also improve LLD macro lookups, but most likely that would depend on custom LLD macro jsonpath complexity.