The one in 13 definitely is possible without super object throw. Don't know about 12, never really tried that.
You just need to practice and move your mouse really quickly. It's not really hard, but you don't really need to cube throw. In 00 it doesn't save a lot of time, same in 09, same 13 :/ so don't do it
in chamber 12 : Don't do it. I do it but it's really hard, you need a LOTS of practice. And it save only 3 sec.. you have to move your mouse really quickly.
An update has been released for SST that adds the command sst_portal_resetisg. This command removes Item Save Glitch and is to be used in place of restarting the game. This is a temporary solution while a more robust and legitimate one is developed.
The reasoning for allowing this is to make the ne