I usually try cradle and sleeping position. Actually it really depends on baby's mood, sometimes my boy can handle a let down in an engorged breast so i will just leave him in cradle position but unlatch him when he appears to be fidgetting to help him breathe better then latch him back on again. you can try pumping out alittle before latching him on if breast engorged or having let down. Alternatively i wait for let down to be over before i put him on again. ( bt my boy super impatient, so i have to try to burp him, walk around to stop his crying before latching him on back again.)
Yeah you should put him in a more upright position, so as to allow flow to be against gravity,but adjust him back to cradle position the moment let down is over, if not baby may fuss cos of slow flow.