With firmware version 2.90, Line 6 took a positive step in the referencing of impulse response files used in your presets. HXEdit now calculates a "reference signature" based on the contents of each impulse response file and stores that in your preset files along with the position of the impulse response in the IR list when exported.
What that means is that you can shuffle the order of your impulse response files on your Helix and when you reload a preset, it will relink the correct impulse response file to the preset independent of the IR's position in the list. You no longer need the correct IR loaded in the correct position, you simply need to have it loaded on your Helix. In the event the required impulse response file is not loaded, HXEdit will alert you when loading the preset that "The IRs associated with the following blocks could not be found".
Since the reference signature is calculated based on the contents of the impulse response file, it should be the same for every Helix user, so you can now share your presets with others, and as long as they have the required impulse response files loaded into their Helix, HXEdit will make the connections.
Interestingly enough, also saved in your preset file is a list of all of the reference signatures for impulse response files stored on your Helix at the time and the position they were stored in.