You can study Bodmer's library code and examples. Likewise, there are several libraries that render fonts faster in hardware.
I was intending to build your exact project. With your ILI9488 and with more common parallel displays.
Demonstrating mods to your project is the best way to show you any algorithms.
If I or someone else just demonstrates a general purpose aketch, you are less likely to study it.
Somehow it is frustrating when a member spends their own time on a problem and the OP is not prepared to make an effort to read the replies.
David.