That depends greatly on the MSC. Many have their schedulers so swamped that there is no chance of a reply to anything but an emergency, if that. Others are positively chatty.
If you are new to this world, it may be difficult to realize just how many shoppers may apply for a single job; dozens, scores for some. If it's not "first come, fisrt serve, it may be that the shopper with the very highest average score gets the shop. Many, many factors.
Based in MD, near DC
Shopping from the Carolinas to New York
Have video cam; will travel
Poor customer service? Don't get mad; get video.