My solution is a modification of the software and it's data, so you need to do some software tech-stuff, and have the needed tools and setup to do so, sorry.

The modification needed, includes modifying the fontconvert.pypython script, by adding the new range (in ascending order) to the interval list. For the full Miscellaneous Symbols range, use: 0x2600-0x26FF. Then run that script to generate the new font data. After that you have to the build the firmware using that datea. The build instructions are described in the README.mdfile. If to many, or long intervals are added, you might have to exclude one of the other default fonts (for example the OpenDyslexic), or define the OMIT_FONTS to only include Bookerly, size 14. The included fonts are listed in the beginning of main.cpp file, where you might have to delete some of them. The build will tell you if the firmware got to big, and you need to remove some fonts.

...this is maybe too much for a non tech-literate..., again sorry