Comment by Theodores

Impressive! I had to peek at the SVG file and it superficially looks good, however, as is the case with everything AI, the more you look, the more it doesn't make any sense.

By now AI should know of the DRY concept. But no. Hence the keys have a rounded rectangle for the key shape and another rounded rectangle for a clip path, to prevent text overflow. There are 72 * 2 = 144 identical rectangles, when just one would suffice (in the defs), with this being cloned once for the clip path, and 72 times for the keys.

I would not expect SVGO levels of optimisation (rounding numbers, that sort of thing), however, the human, if writing out the same thing for the 72nd time, might think 'is there a better way', to get the manual out. A graphics program such as Illustrator would not do that, but AI 'should' because AI.

The above is not criticism of your work, just an observation regarding AI SVG capabilities.