The Greyscale styles are not very efficient and waste a lot of memory. In addition, you have a lot of mixed version syntaxes (OS5 and OS6 have very different style builds and mixing the two wastes even more memory).
If you want to fit considerably more on your board I recommend generating all of your styles in my current library. The library styles are written to optimize space and if you build all of the styles in one version it saves additional memory.
I’ve converted a fair amount of Greyscale styles and made them considerably more efficient, and the rest are typically built from modifying library styles, reading the comments will tell you how to rebuild yourself.
For even more space savings, you can use my Config Helper. When used in combination with the Library, Using Functions and Style Arguments you can further maximize what fits on your board. Read here and watch the videos at the top of the tool.