I have known airfields use "Roger, take-off at your discretion" - making it clear that it's okay with the A/G operator, but ultimately entirely up to the pilot.
I've also known airfields where seeing what's on final approach from any sensible position to line up from, is very hard.
So, for example:
"Popham radio, G-ABCD, ready for departure on 26"
"G-ABCD, take off at your discretion, but recommend you wait for the Cessna on finals"
Is pro-safety, surely?
G