I loved Bookerly for years, but have switched to Literata
https://fonts.google.com/specimen/Literata
Both are great, but I think Bookerly is better for work reading (slower reading, taking in all the words) Literata leisure reading (enjoyable and easy to read at pace). I mainly read for pleasure on my Poke Pro so Literata is the better choice for me.
In Moonreader my settings are
font: 20
paragraph spacing: 70%
line spacing: 4
margins: 20
left justified (massively prefer this to justified, which tends to be the default and is difficult to change in some devices/apps)
I also strip all custom formatting from books in MR