A little update
Im finally back from my move, and i'll be getting back to Pangu Lagoon soon
progress may be slow, Cruddy internet problems (and i hate comcast )
Dont expect me to be on v1.47 just yet, im a bit behind and polarized, plus i want to get working on changing the lemmings to look like milla soon
so give me time to get things finished and updated
other than that, finish the rest on v1.43 update later
because GOD i was bored, during my downtime, I 100% Smash 3ds, i beat megaman 4-6, i beat a bunch challenges in legacy collection, and i have drawings to scan, and hell i even have some ideas planned (like a Discord)
anyways, i'll be heading back to the lagoon return with a blue robot that i have to kick to access its internal database, cheers

                                                                                                                                                                                                                    -GigaLem

With special-casing for the first two strokes, we could probably use the following rules to continue bashing:
3a) There is removable terrain withing the next 14 pixels (and at the correct height)
3b) There is steel within the next (14-5*n) pixels (and at the correct height), where n is the number of previous basher stokes that haven't removed any terrain.
3c) There is steel within the next (19-5*n) pixels (and at the correct height), where n is the number of previous basher stokes that haven't removed any terrain, and where the basher has made at most 3 strokes.

There are still some problems with this:
- In situation i) above, one can manage about four basher strokes before removing terrain for the first time.
- I can still cook up situations where terrain behind a steel wall determines whether a basher turns or not. Most notably this occurs when putting a steel wall (with possibly some usual terrain behind it) after a steel slops (like in möbius' example).
Moreover I am very worried that such complex rules like the above might introduce new glitches, that only occur in very specific situations and on very specific basher strokes.

Unless someone has a brilliant new idea, I therefore tend to choosing some basher mechanics that fulfil only two of the following three conditions:
C1) Bashers turn at steel only when standing directly in front of it, cf. http://www.lemmingsforums.net/index.php?topic=2579.0
C2) Steel-bashing to turn climbers is possible and it does not depend on the exitance of normal terrain behind the steel wall, cf. first post in this thread.
C3) On steel slopes, bashers do not continue bashing, cf. the example level that möbius posted in this thread.

Presonally, I am in favor of keeping the current V1.47 behavior and accepting that C3) is not satisfied. Reason:
- Not-C1) does have too many weird consequences and whether a basher turns depends strongly on the pixel they started bashing.
- "Terrain behind steel"-influences are less discoverable by players than the C3)-behavior. In other words: Players can probably guess what conditions need to be satisfied for Not-C3) to happen, once they see it. Guessing in what setups the "terrain behind steel"-influence comes up (without already knowing the cause) is far harder. 
Therefore I deem ignoring C3) the most user-friendly option.
Note that the Lix-basher satisfied C2) and C3), but not C1).