Removed the dialogue, long press will toggle between lowest and Max brightness, configured the tile so you can make it any number, added comments

Automatically set brightness 1.4
Set the brightness level, or set adaptive brightness using a seek bar
Set the brightness level, or set adaptive brightness using a seek bar
Sorry but there is an issue with the forum where it can't send out emails.Because of this the forum is in read-only mode at the moment.
You can find the currently known issues with Tasker and possible workarounds here.
In the mean time you can ask your questions here: See you soon! João Dias