If you load a map at a normal resolution(4:3) in multiplayer and then do a "vid_restart" into the widescreen resolution it should work(set r_customwidth and r_customheight then change r_mode before the vid_restart). Naturally this is tedious since you have to do it at least once per session(It may need it every time you join a new server). The custom width and custom height values should stick but you will need to go back to a 4:3 resolution. Obviously this isn't really a practical solution though.

I have all the star wars games now on GOG(Except for Rebel Assault) and a fair number on Steam. The Mac builds on steam were done by Aspyr(here's hoping GOG could eventually work out a deal with them to get JO and JA here as well but I'm not holding my breath).

Anyway the Mac version on Steam appears to be DRM free. I can launch the downloaded game without a net connection or steam even installed(well I assume I can since the downloaded app does not launch steam when you open it) though naturally you still need to download it from Steam. But the mac builds on steam have been updated with a fix for this bug that I can verify was in the PC build as well as the older Mac build(the bug not the fix) since all my old versions failed to work correctly with the r_custom" " and r_mode method. I will also say that they offer native widescreen support in the Mac builds.

So basically hope they release a mac version though that may not help you and use the workaround I said in the top paragraph if you really need it to work. And yes hopefully OpenJK builds will fix it.

Use openjk

OpenJK is not working anymore on JK2 MP if I'm not wrong? But I have a config for JK2 MP, which eneables widescreen and wider fov. It changes also the lightning of the maps a little bit. But its not bad. It activates also the well-known ping-diagram from the quake III engine. Are you interested at this mp config? Shall I attach it here?

For JKA: I think the fov think is the problem. Somehow I had also problems to set the correct fov for multiplayer. I had also crashes. However, is fov command even working in JKA MP? In OpenJK that should be fixed. I downloaded open JK, but was not able to install it. Maybe i have chosen a bad dev source? Has an Error Message for me.