I noticed that after some update (I believe with 3.0.3) the numbers for references are drastically bigger now. Yes, it is easier now to tap them, but from my point of view it disturbs the reading experience. The line with the footnote now stands out of the text and is emphasized. This looks not nice aesthetically nor does it meet the importance of the footnote or reference link. (A reference is just a reference; many people even do not worry to look them up).
And it is not consistent as the attached picture with footnote
and reference numbers demonstrates. And as it one of the use cases mentioned in
the rationale for using both apps together, one could use Marvin and Marvin SxS in order to look up the footnote, so no tapping at all would be needed.
I therefore suggest to provide an option for the user to toggle between small or big reference notes.