When trying to use --out-format to emulate some info provided by --progress, I discovered that it is impossible to make multiline log formats (it removes/ignores newlines completely), and also changes tab characters into the character sequence "\#012" plus the wanted tab.
Example (with tabs shown as \t):
> rsync -a '--out-format=%n
\t%l %b' blah/ blah2/
file1\#012 21310 21353
file2\#012 10654 10697