Calling tidy_plus_plus() arguments for tbl_regression()?

[ddsjoberg]

What is the best way allow users to pass additional arguments to tidy_plus_plus() for further customization?
Things I value in the solution (which does not need to implemented in the next release):

• functions with few arguments
• the majority of users have a good experience with the function and are not overwhelmed with too much information when encountering the function.
• tables are highly customizable

1. Allow users to set default values for tidy_plus_plus() via gtsummary theme elements.
   • Pros
     • Easily implemented
     • Can make theme_gtsummary_plus_plus(<list each additional arg to modify>) to easily modify tidy_plus_plus() arguments
     • Does not overburden new/majority of users who may not need this type of feature
     • This can be implemented now, while we decide on whether to implement other options
   • Cons
     • Writing/Saving gtsummary themes is not easy. Although, users can use an exported theme.
     • Not easily discoverable by the advanced users
2. Add a tbl_regression(tidy_plus_plus=list(additional arg)) argument.
   • Pros
     • Will be visible to users, so advanced users can discover the option
   • Cons
     • I don't like adding more args to the function, especially for args most users may not use? But this is only one arg....

[larmarange]

If new options are added to broom.helpers, solution 1 will require an update in gtsummary as well, which is not the case in solution 2.

An additional thing to consider: if we develop addition experimental tidy_ functions in broom.helpers, I do not know if we should make them accessible through tidy_plus_plus() or wait that they are stable before inclusion.

For advanced users, all options of tidy_plus_plus() are also available through individual tidy_() functions.

Maybe a third option is to implement an extra_treatment argument allowing to pass a custom function that will be applied to the result of tidy_plus_plus(). It could be any broom.helpers::tidy_ function or any function developed by advanced users, so event more flexible that the current options 1 and 2.