Being able to share fields across forms is one of the most unique and useful functions in forms. It is so useful that it is getting used more and more in complex business processes and it does lead to something that I have to consistently warn about.
If you copy a form 10 times, you will have to do 10 times the work to update it, and you will have roughly 10x the chances of making a mistake when updating.
I have been thinking about how this could be resolved, so that fields could be shared without the burden. I think a Prefab option would be a great solution.
It is crucial to be able to change properties across forms while using the same variable which is the existing functionality. However it would also be nice to be able to setup a field as Prefab, where we could update the master Prefab and push our updates out to any other forms using this Prefab. This would be in addition to the normal fields.
Or if the Prefab supported slicing, where you choose which properties to push AND to which forms on update, then it could eventually replace the existing functionality in its entirety.