[stumped]

Did that a while back but I can't get on with how moon messes with css. Syncs well, as you say, writing only the page number to cloud. And has lots of features.
But What bugs me is when you have a book which styles the 1st letter of 1st sentence of each chapter, or does some more complex stuff with spans and with small caps also to the opening words. Moon tends to add spaces between styles that look all wrong, and editing out that stuff can be a chore if there are lots of spans.
I bought it and persevered for a few weeks but went back to mantano, as it was then called

To give due credit to both moon and bookari, when I switch to reading an unconverted amazon purchase in the kindle app, that feels much less user friendly and somewhat featureless.. Something like peeking to see how many pages to chaper end, without accidentally losing your current page, is way less easy. Moon can do that as a footer option. Kindle can only do time to chapter end, at not even that sometimes.
And kindle app has only 3 fixed background colours.