Libby, the new Overdrive App

[stumped]

sorted I think.
As I'd bought a 3rd tablet( fire HD 10) on black Friday i thought lets install to that and see if 2o out ot 3 sync. yes. so uninstalled and re-installed the odd one ouet. I think it is good now.
maybe I;d signed in inconsistently . i am now sticking to sign in with overdrive .y.e wilt email and passrod, not with library card. and sticking withl libby only , removing overdrive android app.
I'd still like to use my fonts though, - caecelia, bookery etc, I can get them into moon & bookari but not into libby
and if my read progress is in a cloud somewhere I would like to to know where, and who sees it. [ so I know what books NOT to checkout to avoid having a swat team and bomb disposal unit on the doorstep ]. actually I am not that paranoid but there must be some cloud storage of "my" details going on & I did not notice the bit where i consented to that.
of the reader setting options I have gone for customise, justify , sans serif, and sepia background, line height 2, and 2 column landscape. that is reasonably close to my kindle reader and moon+ settingsm except that I prefer a green background.
It was not at all obvious how to do highlights & notes. I thought that was not supported, but as the blurb says otherwise I poked around until something worked !
if they keep enhancing it it has potential to become a favorite app, it certainly makes picking and reading library books very very simple on tablet, and less tedious than waking through the drek that is Kindle unlimited. ( KU have given me another 3 month free trial - that's my 3rd! - I think they are getting desperate - but so hard to find stuff. can't trust the reader reviews as we know they are very spammed and bot driven... )
also 1st imressions of the fire 10 as a reader / streamer are good. I may put my classy old HDX 8.9 up for sale as i don't need all of its bells and whistles... [PMs welcome ]