[fish45]

drawing on my kobo using the Plato sketch program is actually super responsive. I'm not sure why but it seems that the refresh rate is fine and e.g. flipping a page or scrolling takes a long time for other reasons than the refresh rate

[Doxin]

When drawing it can do very small partial refreshes. Sometimes E-ink screens also have a fast refresh mode and a high quality refresh mode. Doing the fast refresh ends up with ghosting since it doesn't give the pigment particles enough time to move. Using it for some things is fine, but only if you later also do the proper refresh.

In practice you'll see full screen refreshes be the high quality type, and smaller refreshes being of the fast type. That said plenty of e-ink displays don't bother with the fast refresh or even with partial refreshes and just always do a full screen high quality refresh. For E-books that's probably fine.