Allow variable (other than default 2) number of supervisors
I believe the University of Turku requires at least one supervisors, but it is common in our department (Faculty of Science/Department of Physics and Astronomy) to have three supervisors (perhaps there are more). I have checked a sample of recent theses produced by our department, and found at least one work with a single supervisor and at least two works with three supervisors. Mine is the third one to have three supervisors in this sample, and I obviously cannot add third supervisor using the current style.
The supervisors/reviewers/opponent (2 + 2 + 1 hardcoded) are set up with \TitleBack
https://gitlab.utu.fi/samnuutt/annales/-/blob/master/example.tex#L97-101
which accepts 5 arguments (hardcoded)
https://gitlab.utu.fi/samnuutt/annales/-/blob/master/annales.cls#L502-505
It could be nice to have an option for 2 and 4 supervisors, arranged in a table, which will allow to input any number of supervisors from 1 to 4, covering all possible cases. Otherwise, people like me have to dig through the cryptic TeX style files to change default settings.