I like the idea of being able to show the bezel style notification that "Display text large" uses, but I'd like to be able to make it smaller, and possibly customize it's display position and color etc. Size being the most important customization.
Thanks,
Noted. Although there is no obvious way to configure that given it is a menu selection in a variety of actions.
I just joined the forum to request the same feature. When I first applied a ‘display text’ action in a macro I was hoping it would use the same moderately sized bezel overlay as seen in the ‘Activate/Deactivate Macro Group’ action when ‘Display Toggle’ is enabled.
I hope you will consider expanding on the ‘display text’ action set.
Thank you.
Years later, please include me on the list of people wanting more control over the Display Text Large action. I'm looking for easy duration, size, opacity, and screen target. I really like a floating text action more than the HTML option.
You can change the duration - see this discussion thread https://forum.keyboardmaestro.com/t/display-text-large-can-the-duration-of-the-display-be-changed/5296
Oh - just saw the other discussion going on about this.
Are there any updates on this feature request? @peternlewis
I'd like to be able to control the size, position, and color of the display text large too.
Maybe not the same action, but something similar to it that allows us to customize the display.
You can do this using the Custom HTML Prompt action.
In fact, I'm pretty sure there have been topics/posts about using the HTML Prompt for this very use case. A Forum Search should find these.
The Custom HTML Prompt in KM does not offer a transparent/semitransparent background, as the Display Text Large action has, and as BetterTouchTool offers. With BTT, people can build some cool stuff like this:
If I were to use the Custom HTML Prompt to replace the Display Text Large function, I would probably use the BTT floating HTML because of the translucency background option. But, although I've been using the Custom HTML Prompt in many places, I would still prefer not to use the Custom HTML Prompt action if there are other easier ways.
Lastly, since @peternlewis "Noted" the request. I was just checking in to see if there have been any updates. 
No, there are no changes on this front.
As noted, the display is typically invoked as an option from a menu, and so it doesn't really have any way to configure it. It would need an entirely new action, or new UI.
And to allow all the customisations would require a lot of code and options, so more likely I would expand the Custom HTML Prompt to allow transparent backgrounds and borderless windows (if any of that turns out to be possible).
Thanks for your reply. I'm patiently waiting for this feature to be available in the future.
Personally, I see transparency as nothing more than eye candy, and it decreases readability. I see no functional benefit to it. I know there are others that like it, and that is fine.
My 2¢ would be to put other items that provide new capability, new functionality, higher on the KM to-do list.
"expand the Custom HTML Prompt to allow transparent backgrounds and borderless windows (if any of that turns out to be possible"
This will be amazing because Custom HTML Prompt is one of the most powerful actions but often overlook feature.