Unfortunately, Marvin isn't being consistently developed (only occasionally now, it seems), the
official bug-tracker at GitHub has been pretty much dead/ignored for a couple of years now... so, we shouldn't really expect
anything from the app from now on. I know I don't. If Kris one day finds the time again to improve something in Marvin (however, quite a few things got
worse in Marvin 3 compared to earlier Marvin versions, although overall, Marvin 3
is an improvement...), that will be a great and
unexpected bonus for me.
And no, I'm not "blaming or shaming" anyone – just stating the facts. I have full understanding for the fact that there apparently is no livelihood to be earned from developing a top-quality e-reader app. And so, we must be content with
approximations (very rough, in many respects) to the ideal.