I think the idea of ed is to embrace the edit-compile-cycle. So the error tell you the specific line to go to. Then after the obvious errors are out, you do a full printout to handle logic errors.
The idea of Ed is that you have a large spool of paper and you make little editing marks on the printout until you decide you've reached some threshold and then print out a fresh up-to-date copy
It’s always fun to figure out the path through the error messages that changes the error line numbers the least, so you don’t have to search or recompile.
