Because i kinda needed this, i created this small plugin!
github.com/iamntz/sublime-per-project-builds
And because i hate when a plugin will overwrite my key bindings, this is not include any such things, so you need to add
{ "keys": "ctrl+shift+b"], "command": "build_selector" }
in your keymap file.
That’s it. I hope will be useful to someone else too