Thank you!
I had an on/off relationship with Koreader for one basic reason: I did not find a suitable font for me (just a little more emboldened than usual) to use with Koreader.
I just found one by chance (
Amasis30) and so I am back. Most other things on Koreader are very nice. Sometimes the settings are a little tricky to find (
defaults.lua, cr3.ini, "render styles") but with a little care, one can always find a suitable solution for the basic and -for me- most important features.