I did find that spending more time out of the saddle (eg. standing up a bit while coasting over bumps, standing while climbing, etc) did reduce time under pressure on my sit bones. But I eventually got to the point where I just didn't get sore around the sit bones any more.

OTOH, if I didn't change the saddle on my other bike, no amount of standing would compensate for the saddle being too narrow for my sit bones - and no amount of padding would have helped either.

The climb up to my house is long enough that standing the whole way is simply impractical for my level of conditioning. Articles on climbing technique tend to advise alternating sitting and standing, or not standing unless absolutely necessary. In that famous climbing battle between Il Pirata and Lance Armstrong, they both alternated between sitting and standing that 20 km climb.