The enchanted soil is unable to be silk-touched, not sure if this is intentional or not. If it is, could there be a possible config option for it in the future?

that is the intended design

Silk Touch (and the Weight lens) were specifically made to ignore Enchanted Soil. It's not meant to be movable [Citation needed]

EDIT: Looking through the changelog, version R1.6 177 fixed people being able to pick up enchanted soil with silk touch, so it is definitely an intended feature

It's 100% intentional, Vaz has stated that she has no plans to allow moving Enchanted soil.