Stick stickies to desktop permanently.

Pressing Win + D to show the desktop hides sticky notes if they aren't being shown top of the windows (all windows).
Is it possible to by default not make notes do that, and if any note isn't all too important can be toggled to hide on showing desktop.

Apologies if it's already fixed or a feature request.

You can try "win + m  and "win + shift + m" to reverse , it minimizes windows and stickies cannot be minimized so they stay visible .

The second part is more dificult but can take a look at "stacks" there you can select less important ones in a different stack to show/hide .

https://www.zhornsoftware.co.uk/support/kb.pl?q=00008
@Admin I just noticed this in the Knowledgebase. Just my two cents.

For one, the way you have phrased things seem more like a personal opiniated bias, instead of giving a technical reason why it cannot be implemented. This is very discouraging to hear as a reply why something will not be implemented.

Second, why are we assuming stickies are running as a window?
"You're the person in charge of your computer, and when you issue commands, no application should decide it knows better than you and not obey!"
"Stickies are windows just like anything else..."

We're in charge of using stickies and we're the ones telling it to stick to desktop. How is the application deciding it knows better if it comes as an option for us USERS to decide?

Can I pin Stickies to the desktop?

The question was this in particular. It already assumes the user is in fair knowledge of what they are doing and it's not the application deciding it for them.

And, why are we assuming stickies are windows? There are plenty softwares that act without being assumed as windows, Rainmeter is already an example. And the, "potentially ripped of stickies" software, Notezilla can easily do that. 

If you don't want to add the functionality then you can state it so that it doesn't seem to be the right kind of idea for stickies in your mind. Otherwise, the argument thus stated in the knowledgebase holds far less value.

User is clearly aware, user is the one who wants the stickies to stick to the desktop, and stickies should not necessarily act as windows. In fact, there's already a toggle for that to show the stickies as an icon in the taskbar or not. That itself is an indicator for why stickies shouldn't necessarily act as a window.

EDIT:
Also about the Win+M and Win+Shift+M shortcuts. I am very clearly aware that those are to minimize the windows. The point of Win+D is indeed to show what's on the desktop. It's not to minimize the window(s) per se. And the point of having the stickies pinned to desktop is to be able to see the notes on the desktop.