That's one of the strengths of GNU Health. No matter how small or
large your installation will be, my advise is that you should create a
module for that institution, so you can put your own reports, views,
...
In that way, you work on your own context without affecting the
standard and the upgrade process. Then you can inherit the models, and
add the fields you need.
Of course, many times there are things that are useful for the whole
community, so please let us know if you find something missing that
will be of benefit for future versions, and we'll incorporate it to
the standard release.