Do line breaks help synctex? Does it for example help to add hard line breaks after 80 characters instead of writing a paragraph per line?
Just the other day I answered another question about how SyncTeX works. That elaborates on the SyncTeX file and what it actually contains. I'm going to assume that you know what the SyncTeX file contains (and obviously that we are talking about hard wraps).
So to answer your question: It may help. That's because the column specification in the SyncTeX file is optional and rarely written. So if your line is very long you are likely to only get a line reference (and only the line reference without column) which is not ideal in case you actually want to use the synchronization and edit at a specific point.
Please do not forget that the SyncTeX command line utility/the SyncTeX library actually deals with many different cases but the actual synchronization is done by your DVI/PDF viewer and your editor. That means in case of imprecise tools you might gain real benefits but if your setup is working "perfectly" (column spec in SyncTeX file, precise PDF positions reported by viewer, editor supporting exact jumping) it might stay the same as before.