Many forms, typically those for journals, have locked filters that get populated with user id's and user group id's specific for that user. That makes sharing workspace objects for those journals impossible, because the importing user cannot make changes to the existing filters.
Trying to import a workspace with such a form included on it, even if the user is a System Admin, results in the following error:
"The imported document contains one or more personalized lists or tiles that failed security validation and cannot be used in this workspace. The list(s) that failed validation has been removed from your workspace."
Those filters should be using methods that provide the appropriate results regardless of the user running them. An example of this is how other forms, like "My cases" work.
There is a forum post, https://community.dynamics.com/365/financeandoperations/f/dynamics-365-for-finance-and-operations-forum/275653/user-personalization-import , that includes details on how one user implemented such filters via customization to overcome this issue.