Hi Laura,
Welcome!
I'm a member of the Documentation Team who (at the moment) focuses on Calc aspects.
I've been chatting to Ilmari Lauhakangas and wondered whether you would be interested in helping with some of our current activities to improve Calc's documentation? There is plenty to work on but I will try to avoid scaring you off by covering too much!
One area where you might be able to add great value quickly is in our Calc Functions wiki (https://wiki.documentfoundation.org/Documentation/Calc_Functions). Within the 500+ pages accessible through this section of the TDF wiki (one page for each of Calc's functions) there are 63 pages covering financial functions. As a mathematician working in quantitative analysis, then I expect you will know a lot more than me about what these functions should do - perhaps you could review their current descriptions to identify any corrections or improvements that could be considered?
Another task you could certainly help with is reviewing the LibreOffice 7.2 Calc Guide chapters, when I've completed the updates in a few days time.
Please let me know if these activities interest you.
Regards,
Steve Fanning