I haven't tested this yet - but I'm curious if I'm doing a custom dict with newlines in the definition - can I just use the "field enclosed by double quotes" (") method or not?
Nope, at the moment the only way to do them is to insert the special character Unicode U+EAB1 () in the place where you want that newline to be. (one of those embarrassing little Palm OS era legacies we haven't gotten around to fixing yet)