At the moment, clearing the old position then printing is the fastest way to do it http://forum.m5stack.com/topic/173/how-to-avoid-text-flicker/3 you can print to sprite if you use the eSPI library and that'll gain you a few ns on the chip but I think the bottleneck is the SPI protocol, that's what Bodner was saying.
You can wrap the clear and print in a function which will make your code as concise as using an object.
Sorry about comments absence in code - they was on local language, and dropped automatically when downloading. Code optimisations was only on chess engine, other parts made more rudely.
Glad to hear our issue is cleared.... its understandable for anyone if one has had issues with something in the past to be sensitive - even more so when digital rights are involved as this can quickly become a serious matter.
I think I have some similar views to yours in that area.
OK well all the best with your work..... I stay tuned ! Jimi