It would seem to me that, unless I am missing something, none of the Delta classic-design bath valves in the Mix and Scald-Guard series have any volume adjustment.
The only "classic design" SG valves with volume adjustment were in the 600 series, all of which were discontinued in the late 1980s. Those exact SG models with volume adjustment were 603, 604, 607, 613, 614, 623, 624, 637, 638, 643 and 644.
The old 1500 series Monitor valves did have both temperature and volume adjustment.
The low-end 1300 and 1400 SG valves have no volume adjustment; therefore you must move up to the two-handle 1700 and 1800 series.
That is the way they were made, and your question is? ALL single handle valves with rotary action, ARE temperature only controls. You either need a second handle or multidirection action handle to get volume control added
Licensed residential and commercial plumber