Most 1.3.5 repacks integrate stable branches of Marlin 1.1.9 or Marlin 2.0.x optimized explicitly for the Chiron's Trigorilla motherboard.
While older versions of the Chiron firmware were perfectly capable, version introduced several under-the-hood refinements: anycubic chiron firmware 135 download repack
This allows you to fine-tune the Z-axis height in micro-steps directly from the screen during the first layer of a print. Most 1