When a FB interface changes currently the FB with the old interface must be manually deleted and all connections manually redone. This is error prone.
A refresh (via rt click like clone) could check for a new interface, name the connections / variables added or deleted and ask if the FB should be replaced with the new interface.
Event connections with no name change should stay the same. (most important)
Event connections to events deleted should be deleted, possibly with an additional warning IF it has connections. However the previous message about the interface changes will serve as a warning too.
Similarly variable names not changed should not change and values kept.
Variables deleted should be deleted.
New events and variables should be added.
A first version is available in cset 482f26c3af1b. The user have to manually activate an update by right-clicking one or more FBs and pressing "Update FB Type". After this no more questions are asked by the IDE.
This feature is now available already for quite some time and used a lot. Therefore I closed this issue for now.