On a client's site, the Post Preview option is turned on to reduce the amount of bad posts. However, as an admin, this is a real pain - I hate having to Preview first and then Submit. So I did some digging and found out a couple of other people are also interested in a solution. A chap by the name of Markus Petrux has even released a small module (for 4.7) that allows certain roles to bypass the forced preview. You can select which roles in the Access Control page. His module can be found here. Thankfully, to make it work in 5.x, all you need is a .info file. So, simply create a file called bypass_forced_preview.info and put the following text into it:

Make sure the module file and the info file are together in the same folder in your sites/all/modules folder.

That should do it. Thanks to Markus for a solution to this annoyance.