Tweeter or compression driver?
A compression driver is a plane wave generator, a regular tweeter is not, so the solution cannot be the same and the usage is not the same too.
We can constrain the radiation of a compression driver and choose a radiation angle, but with a regular tweeter it’s more difficult to do it without create a lot of problems.
It’s why we talk about wave-guide for tweeter and not horn, with a tweeter we just “guide” at 110° horizontally the tweeter.
But with the use of modern phase plug we can reach 100° without problems:
It’s why we dedicated tweeters for close distance or monitoring usage and compression driver for medium/long distance usages, as see in the guide page.
At mid-distance, so with a 90° coverage, horn with compression driver will be more adapted.