hi i have 2 good ideas that would be very helpful
1- a wall that lets elements go through one direction and the other direction wont permit anything!
2- a wall feature: you click a wall and click a button over the wall menu and the search element tab pops up, then you choose any elements then you click a bunch of options. now the wall only permits or denies the chosen element!
ex: i have a gas wall, but i dont want hydrogen to go through, so i click on the GAS WALL and click hydrogen in the element search tab and click ok (because maybe i want more elements to deny or permit) then click deny and BOOM! the wall only denies hydrogen!
:/ seems legit