For everyone who wants the forums to be easily view-able in a phone browser, I found a crude but working solution: use prosilver. If you don't know how to change the board theme to prosilver, this is how you do it:
1. In the User Control panel, go to "Board Preferences"
2. Look across the section named "My board style". You should see "smbx" in a dropdown menu.
3. Click on the dropdown menu, select "prosilver".
4. Save your settings.
Note that if you change your settings to prosilver, it'll be the same both on mobile and on desktop. As well as that, prosilver doesn't have Project Wonderful built in (yet), so advertisements won't appear if you're using prosilver.
E: there's another thing: signatures are not shortened under prosilver. Though if you're like me, then you'd think that scrollbars are unecessary, anyway.