Climb until the warning stops and clear of terrain. I know what you're getting at, but I'm certainly not going to level off at the MSA I think is valid for the quadrant I think I'm in when my heart is pounding and trying to remember the MSA from the briefing 20 minutes ago. I'll simply look at the chart right in front of me as I'm climbing.
Look, I'm not suggesting that I fly around with no idea where the terrain is. My point is that as it is briefed, it is simply thrown out there. Then when we are cleared lower and lower as we're vectored onto final, every single pilot I have ever flown with, Captain or FO, always accepts and descends below MSA. A conscientious pilot would ask what the MVA is, but I've simply NEVER heard that request. Not a single time. I have asked for it once, as I was given a vector to intercept final 100' BELOW the charted altitude for the segment I was about to intercept. But that's it.
I'd love to hear from somebody who actually refused a lower altitude because it was below MSA and that action saved them.