Thanks Simon. I tested specifically the Lix 64bit binary in wine last night but I was unable to get it to run. I can't tell if it's my wine config or not, but for your benefit I'm attaching a traceback of the error. I'm unlikely to try this approach again since it's more complicated than building from source.

Today I tested building Lix natively on macOS (10.15.7) and I can report it does work well. I've played several levels (all great fun) and no bugs observed yet. I'll be mindful of the bug you mentioned though and read through the workaround thread if I encounter it.

Well after all that effort last night, i just got original Lemmings running in DOSbox Staging with minimal effort! I used a different source for the original game files (a famous site which was recently sued by a bunch of awful publishers for lending out digital books, i'm sure you know it, and i'm not sure the rules here about mentioning download sites....) and it worked like a charm.

Next time I need to get a DOS game running on MacOS I'll go straight to DOSbox instead of trying Wine. Way less hassle!

About wine on MacOS and 32 vs 64bit, see here: https://formulae.brew.sh/cask/wine-stable My wording may have been a bit confusing.

I haven't tried natively compiling, actually. I was poking around pretty late at night and I didn't realize I could do that on a Mac, I thought all the compiling would be Windows-only. I will give that a try. I also think I got a bit confused about NeoLemmix vs Lix, and I thought they were part of the same project. Thanks for that info!

I signed up to make this post as a warning to others who might try to go down the path I did. It is inadvisable to spend time trying to get any of the 32bit Lemmings or Lix executables to work using Wine on MacOS, post Catalina. Support for this sort of 32bit application has been dropped. Wine will still attempt to run the executables in 64bit mode but will crash with a fairly generic error message. Unfortunately I learned this after about 2-3 hours of fussing around trying all sorts of different things to resolve the error. Don't be like me!

It may still be possible to run things on MacOS in DOSbox - I am not certain - but I also ran into some trouble trying that. I know for certain it is possible to emulate Windows (with VirtualBox, for instance) and then run the executables in the virtual machine that way. Certainly a lot of work, though.

Hopefully this post saves someone a bit of time : )