Zandronum

So, I decided to copy some of my Zandronum stuff onto this here Macbook and download the OS X release. Whenever I join a server with Doomseeker, or try to launch Zandronum offline, it keeps loading up Chex3 without letting me choose.

Am I missing something blatantly obvious here?

Not sure if this works on OS X but on Windows, if you hold the Shift key when opening Zandronum, it prompts you to select your IWAD again. The IWAD selection menu also lets you un-check "don't show this again".

Shiftclicking is to edit the name of the file, I tried alt, option, and command keys while launching to no avail.

In your zandronum.ini (might be zandronum-user.ini or some variant), look for queryiwad=false and change it to queryiwad=true

You may also want to change queryiwad_key=shift to queryiwad_key=alt since OS X has a different operation with the Shift key

Setting queryiwad to false still gives me the problem, and there was no such line for queryiwad_key on my .ini.

Whoops. Try setting it to true, I got mixed up
You can add queryiwad_key=alt under the [GlobalSettings] area

Tried both of those out, it still defaults to whatever defaultiwad= is, which is annoying if I wanna simply load up the game quickly and pick which IWAD.

Try removing defaultiwad=
I'm not sure what else it could be