gc impossible if session.save_path depth > 2 ?

Many hosted sites would like to keep their session.save_path separate, within their home dir, but are somehow prevented by the fact that gc wouldn't take place if the path depth is > 2. Because they obviously see a problem in implementing their own garbage collection, as most hosting sites do not offer a shell nor the possibility to set up cron jobs to do that, most give up that, and decide to drop their session in the common cauldron. I went through php code, and it seems that this limit is just hardcoded in there. I mean, is there a valid technical reason for this limit to be there or... gian