Is there any particular level/solution you especially want me to test out?
I think I'm going to start posting future findings on the Lemmings Challenge thread instead, it just seems to be a more relevant place for these findings.
I'll end my last post on this thread with this:
I verified that the glitch involved in the builderless Tricky 9 solution also works on the Mac.
However, I haven't verified the solution in full yet.
You wouldn't think of it, but doing the "right mouse click" (select only walkers) move is a little harder on the Mac. Since the Mac mouse only has one button, you get the effect by holding down the "option" key (the key on the Apple keyboard that looks like a 4-leaf clover, which the emulator substitutes with the right-Alt key on the PC) while clicking.
But unfortunately, at least on the emulator, I find that when I hold down the "option" key, I cannot pause and unpause. The normal key on Mac Lemmings for pause/unpause is just plain "p", and I think when I hold down the "option" key it turns into an "option+p" combination, which I guess the Mac system distinguishes as a different keystroke than plain p.
So it becomes harder to execute right-click moves with precision on the Mac, because I need to first unpause before I can press the "option" key and click. Whereas on the PC I could just hold down the right mouse button while the game is still paused, and then just unpaused and click with the left button.