[quote=“quodlibet”]My workaround is as follows:
- Packages/User/Preferences.sublime-settings
- Packages/User (OS Settings)/Preferences (Linux).sublime-settings
- Packages/User (OS Settings)/Preferences (Windows).sublime-settings
(You can call the folder whatever you want; as long as it’s not “User” 
There are two issues with this setup:
- If you’re syncing settings, you’ll need to sync an additional folder. (@wbond recommends that you only sync the User folder. I actually sync the whole Packages folder, because that’s where I keep my own packages, so I don’t mind.)
- Settings in User will override settings in User (OS Settings). I use these files to setup fonts, so I have simply omitted these settings from my general settings. Because, as @rchl points out, it’s easy to change the font size by mistake, I have actually unbound all shortcuts for these:
Add these to User/Default.sublime-keymap (so that they will work in all OSs):
// Unbind increase/decrease font size
{ "keys": "ctrl++"], "command": "unbound" },
{ "keys": "ctrl+="], "command": "unbound" },
{ "keys": "ctrl+keypad_plus"], "command": "unbound" },
{ "keys": "ctrl+-"], "command": "unbound" },
{ "keys": "ctrl+keypad_minus"], "command": "unbound" },
{ "keys": "ctrl+equals"], "command": "unbound" },
{ "keys": "ctrl+shift+equals"], "command": "unbound" },
{ "keys": "ctrl+keypad_plus"], "command": "unbound" },
{ "keys": "ctrl+shift+keypad_plus"], "command": "unbound" },
And these to User/Default.sublime-mousemap:
// Stop Ctrl+Scroll Wheel from changing the font size
{ "button": "scroll_down", "modifiers": "ctrl"], "command": "unbound" },
{ "button": "scroll_up", "modifiers": "ctrl"], "command": "unbound" },
I hope this helps some poor souls 
Oh, BTW, the bindings are for Win/Linux. You may need to tweak them for OSX.
@randy3k has recently released a new settings manager here:
github.com/randy3k/SyntaxMgr
It doesn’t support OS, but it support pretty much everything else. I thought I’d pester him about it, but then decided not to, because the only use case I have is for fonts, and I’ve resolved that as above. If you have other use cases though, it might be useful to open that issue.
Alex[/quote]
Thanks this this great, but doesn’t help me. I am syncing across multiple machines & platforms, and only sync my User folder and let package control pick up the packages. This wouldn’t work at least without doing it individually on each machine, which I would prefer not to do but would work if I had to.
This has been reported a long time ago and still seems to be the way it is, yet the documentation explains it like this is in fact possible, using OS settings in the User folder.