Couldn't we pass the `JsonDocument' as IN_OUT instead of REF_TO? This had the advantage of direct accessing it via '.' operator. Plus I do not need to be prepared for a possible 'NULL'.
https://github.com/simatic-ax/Json/blob/56789c43fda812f2fa464edbc1008a72b800e7ee/src/Elements/IJsonElement.st#L8
Didn't have checked all usages to it may be better to pass as REF_TO...🤔