The most recent one I can remember was configuring Postfix to perform local delivery to ~/.local-mail/inbox. I had to manually change security context for that directory. Or linking /var/www/foo to ~/foo is an example of something that you might expect to work, but would be blocked by SELinux.
But those are not the kind of things you would do on Android anyway. They use SELinux to strengthen the security framework they already have in place. SELinux is just the last line of defence for implementation bugs and things they might have missed. It would be completely unintrusive.
The NSA presentation is worth watching, they go through various Android exploits that could have been prevented by the policy they developed, without actually targeting those specific exploits.
https://www.nsa.gov/research/selinux/
[1] It’s also because it unfortunately isn’t actually used by most desktop applications, with some exceptions, like Chromium.