I have seen this brought up so many times before, I really wish we had this. Most of the arguments are:
- 'You just don't screen lock, screen lock is for noobs'
- Then dragon and baron would be flipped so it would be confusing
Imo these are not very good arguments, it could be a select-able option like you said, and people (like me) like to screen lock on occasion.
I set my screen lock to the space bar so i can swap between really quickly. This map flip feature does not look like it will ever be in game, I have seen it in forums since over a year and a half ago