It's regal and not royal also this reddit comment explains it well.
The "Regal" page refresh scheme uses a proprietary chipset (that's not in my Boox Note) to do a "partial" page refresh. In other words, it doesn't refresh everything on the screen and usually refreshes faster. The algorithms used to control the chip are proprietary too and may be different from manufacturer to manufacturer (Regal is used in Kindles, Kobos, and Nook Glowlights among others). A2 does a faster page refresh by utilizing "dithering". It effectively lowers the resolution to speed things up. It does tend to leave an "afterimage" over time and **maybe** that's what the "Bleaching" function does (clean up the old pixels). I don't know since my Note doesn't have that either. I have to turn off A2, do page refresh, and then turn it back on if **I** want to "clean" a page. [Here's a good overview](
https://goodereader.com/blog/e-paper...guarded-secret) of Regal and A2 refresh. [And here's probably **more** information than you need](
https://community.nxp.com/docs/DOC-93396) about eink "dithering" and A2 mode.
https://reddit.com/r/ereader/comment...yk9f?context=3
Malcolm