Like everything else in engineering, it would require analysis to see if the idea has any merit. If the lifeboat is being used, you'd have 2-3 people on the rear row near the heat shield and 3 people in the front row. Determining what would that do to the center of gravity and stability would be a central issue of the study. They'd also have to study what the center of gravity would be when it's operated in the normal mode with only 3 people in their normal positions. This is no different than what engineers do when evaluating center of gravity shifts with different passenger loads on multiseat airplanes.

There are several possibilities for controlling the center of gravity, such as shifting where the passengers get seated, moving the seats (and probably the instrument panels), etc. Russia has some very capable engineers. I'm sure they can determine if the idea is feasible and how best to proceed if it is possible.