USB HID "Unicode Page" at 0x10

While I was trying to understand the scope of things that I could reasonably expect my KeyboardIO to be able to send over USB and be received by my Linux kernel and passed on to X to then generate an event, I was looking at and in it I noticed that alongside the “Consumer Page” (0x0C) there is a “Unicode Page” at 0x10.

I know @algernon has talked previously about a new proposal for Unicode over USB but I haven’t seen any prior discussion of this page, which according to the documentation:

The Unicode Page directly maps to the two-octet form defined in the Unicode Standard.

The Unicode Standard, Version 1.1, is the newest version of the Unicode™ Standard. Unicode 1.1 includes
the changes and additions that were made to Unicode 1.0 in the process of alignment with the international
character encoding standard, ISO/IEC 10646-1, which was approved by ISO/IEC as an International
Standard in June 1992, and published in May 1993. The character content and encoding of Unicode 1.1 is
thus identical to that of the ISO/IEC 10646-1 UCS-2 (the two-octet form).

Obviously this specification is dated since Unicode has had codepoints that require more than two octets since at least version 4.0 (April 2003, where the current version of the specification is 11.0 - released in June 2018).

Has there been any attempt to use this page in reports? Does anyone know if it’s supported by Kaleidoscope and/or Arduino and/or Linux and/or X?

Edit: fixed a lost quotation mark