This a Good Question (tm).
It is possible to make the system do what you want, but not as easy as just mucking a bit about in zedit.c.
First off - the commands are stored per zone. This means you need to do some counting to check that the dependencies make sense. And if a line is removed, you'll need to check that the target line isn't altered. The list is maintained for the zone, but adjusted per room - which will make this slightly interesting.
Next, you'll need to do take care of the dependency in the zone reset structures. This means saving and loading another variable for each zone. Or repurposing the if_flag variable.
And finally (?) you'll need to alter the zone loading code to track which zone commands loaded anything. Particularly, in reset_zone() (
github.com/tbamud/tbamud/blob/2f12752373...9f8a4/src/db.c#L2557
) you'll need to change the way the if_flag is used.
As you can imagine, this is quite a lot of work, and most certainly too much to try to write as browser code. That's probably the reason noone has answered you in the other thread.