Here is a trick , that works in Superlemmini , but it is impossible in Neolemmix.
I have posted pictures in this post ,that showcase the trick ( first three are from Superlemmini , and the last three are from Neolemmix ) , but in my next post , I will also post replays , that showcase it.
So , to perform the trick , assign a miner to a lemming that is in the top of a large terain piece , which has the same shape as shown in the first picture.
Assign it as a digger , in such a postion , that it leaves an 1 pixel wall in front of it ( again , as shown in the first picture ).
When it is low enough , assign it as a builder , in order to have it stop digging. It will stop building because of the 1 pixel wall of course. At the first frame , when it turns around , assign it as a basher , so it will start creating a basher tunnel ( as shown in the third picture ).
In Superlemmini , if you do it correctly , it will also remove a part of the 1 pixel wall as well ( as shown in the third picture in Superlemmini ) , and it will be able to make a complete basher tunnel , that the other lemmings will be able to cross it completely , because that 1 pixel wall will not be an obstacle anymore.
In Neolemmix that's not possible. The basher just can't remove that part of the 1 pixel wall , when you assign it as a basher , at the first frame , when it turns around ( as shown in the third picture from Neolemmix ) . It won't be able to make a complete basher tunnel ( like the one it made in Superlemmini ) , because the 1 pixel wall will be still an obstacle for the other lemmings.
You can also , perform the same trick , by replacing the basher with a miner .In that case the results will be the same. In Superlemmini the miner , again will remove a part of the 1 pixel wall , in Neolemmix it won't be able to remove it.
The reason that this happens , is a small difference in the placement of the terrain-destruction mask of bashers and miners between the two engines.