The space has so much going on that it does cause some additional lag when loading. The number of people popping in doesn't help. Once the space is reaching capacity (60 people I believe) a new instance of that space is generated.
I know this doesn't answer your request, but I hope it helps you to understand. It's up to Media Molocule to make any change. Such a change may mean a overhaul (which can be done even if the space is not shut down).
I suggest contacting them directly and using PlayStation®Home Support so that Joystick_Warrior is made aware of the issue and contacts MM officially.
Many times it comes down to the time you go to do challenges. It pays to take mental notes of the time in your area when Home will be the busiest or the least busiest.
I tend to do most of my roaming on Home after midnight. Things tend to be a little less busy then.