Getting batch inspections to work with ExternalAnnotator

Hi - I'm using an ExternalAnnotator to highlight specific lines of code with refactoring suggestions.
In particular I use createWarningAnnotation with a TextRange to achieve this.I'm now implementing running this in batch mode using the ExternalAnnotatorBatchInspection interface.

This is working but throwing up two problems:
1. When the annotation gets translated into a ProblemDescriptor the highlighting is thrown off, since it
tries to find the PSI elements to highlight rather than a line. Any ideas on how to make it highlight
just a specific line in this case?

2. When I open up a batch mode inspection the on-the-fly inspection gets triggered as well and I
get two sets of highlighting - is this avoidable?