you can use both heap programmes, but the setting should be the same. in OSR I use heap no 6 but the heap setting varies for different set ups. yhere is a standard setting for 32 and 64 bit machines, i use heap amount 900 on my rig which seems pretty good...i dont get door crashes anymore. i would try setting the heap low and work your way up until there is an obvious difference. one caveat being that if you set to high, your game may not load. crashes going through doors can be due to missing resources as well, or sometimes even a corrupted save or spawn. If you have not tried this...bring up the console.....type coc center....wait for more than 72 hours....save game and travel back to wherever on the map. this resets all npc and animal etc spawns.