Every once in a while you run into something like this and realize the standard is not just for text encoding but also a kind of archive of specialized notation from different fields.
It makes you wonder how many other symbols are sitting in the table that are still mostly unknown outside the niche communities that originally needed them.
Unicode's entire point being to make "normal software" handle those symbols ;)
There is a combining character that, by its description, sounds like it should be implemented to do the desired thing (U+20DD Combining Enclosing Circle), but my fonts don't render it very well when I stuff geometric characters matching the PlayStation buttons into it.
Without spaces: △⃝□⃝×⃝○⃝
With two spaces between each one so you can see how "enclosing" is getting interpreted: △⃝ □⃝ ×⃝ ○⃝
For the Markdown renderer I'm working on to replace WordPress for my blog, I resorted to shortcodes which resolve to CSS styling the `<kbd>` tag with `title` attributes to clarify and the occasional bit of inline SVG for things where I didn't want to specify a fixed font to get sufficient consistency, like PlayStation button glyphs.
(In all fairness, it's a nerd-snipe made based on the idea that I'll be more willing to blog about things I have nice tools for. I don't currently typeset button presses in any form.)
...though, given the inconsistent naming of consistently laid-out buttons, I think anything that makes its way into Unicode should include something that follows the lead of what Batocera Linux does on their Wiki and with custom emojis in their Discord.
See https://wiki.batocera.org/configure_a_controller for an example of how they look inline but the gist is that it's an outline of the SNES-originated diamond of action buttons that pretty much everyone but Nintendo uses these days and which is embodied in XInput and the SDL Gamepad API, with one of the circles filled in to represent the button in question.
I don't know if that's a good reason to push to standardize controller glyphs to Unicode, though.
(ETA: Plus the other obvious reason more games and game engines are bringing in full Unicode support is localization, especially for Arabic and CJK. We're a bit past the point where AAA games only feel a need to support EFIGS. The Middle East and Asia are huge markets, especially for mobile games.)
For years Ł support on Python on windows for example broke sometimes when imported from poor quality Excel files haha