As you know, tooltips, if configured by the developer, are shown when you hover over some visual elements of the form. In the VCL, in order for such hints to appear, it was enough to enable the ShowHint property, and assign some text to the Hint property of the control.
In KOL, properties such as Hint and ShowHint were not originally provided. We got by (at least personally, I got by) with the so-called tooltips *, which are provided by the system for the toolbar. On this ruler, tooltips can really be useful, at least in the display mode without text labels on the buttons. Simply because it is often not always possible to find out from the pictogram what is done when the corresponding ruler button is pressed, especially when the user is just getting to know the application or rarely works with it, and is not obliged to remember the purpose of each button from time to time.
As for the ability to organize floating tips for any controls on the form, I personally take this idea more negatively than positively. A well-designed interface does not require such a means for constant reminders, especially since tooltips often obscure controls and interfere with work, even if they remain transparent to mouse clicks. If the user is constantly using the application, then such pop-ups can even be annoying (and therefore it would be nice to be able to turn off such prompts if the user so wishes).
By the way, tooltips are historically preceded by the idea of displaying explanatory information in a special field, for example, in the status bar. At the same time, at least such prompts are not intrusive, and do not obscure the "working surface" of the form.
Nevertheless, tips are still needed, and this is evidenced by the fact that the site contains several packages of various authors that implement a similar opportunity. Ultimately, I agreed with the requirement to include official support for pop-up labels in KOL, but as conditionally compiled code. In order for the hints to become available for the KOL application, it is now enough to include the conditional compilation symbol USE_MHTOOLTIP, and the Hint field, in particular, automatically becomes available. Of course, to use the hints mechanism from D. Zharov (aka Gandalf) in the project, you will need to download and unpack a small archive with additional included code (KOLMHTooltips.pas module).
The KOLMHTooltips module, is located in the https://www.artwerp.be/kol/kol-mck-master_3.23.zip archive.