Can I pilon-polish long reads with Illumina short reads to improve structural variant detection?
I'd recommend using Canu for correction rather than Pilon, because it has a component that is specifically designed for read-level correction. The newest version of Canu (v1.7) will track all reads through the correction and assembly process:


  Ensure that every raw read is either corrected or used as evidence for correcting some other raw read. This serves to rescue short plasmids in high coverage datasets, and it is no longer necessary to set corOutCoverage to achieve the same result.


More details here.