Below is an example of getting the gamma values using the legacyArray.
Is this legacyArray okay to be using, or will it be deprecated? What are other options that might be better to use instead of the legacyArray?
const adjustment = require('photoshop').action.batchPlay([layerGetter], { synchronousExecution: true })
var legacyArray = adjustment[0].adjustment[0].legacyContentData;
const typedArray = new Int8Array(legacyArray);
var currGamma = fourBitsToFloat(typedArray[10], typedArray[11], typedArray[12], typedArray[13]);