It’s amazing how much coding is required just for a little change like this. Once I got into it, I realized I didn’t want to create SetDefault routines, but just properly update the IDs whenever the defaults were changed. You never get it just right the first time and after a bit of testing and correction, I’ve now got it working for both GEDCOM IDs and Family IDs.
Then had to make sure that if the user deleted the ID, that a default ID would be assigned, and a message to the user would alert him to this.
Then, a bug: when editing the ID and using the up or down arrow keys to quit editing and move to the next or previous entry, up comes a “Control has no parent” error message. This took a few minutes searching on Google to not be able to find the answer. After a bit of fooling around, all I really had to do was set the key value to 0 so there would be no attempt to process it again by the parent. That bug is solved.