Possibilities on code change to implement pseudodatatypes

Greetings

I understand the complexity of implementing a pseudo data type when
passing it over parameters, or using it when creating an object.
vide: git grep pseudo | egrep -v -e "po|out|sgml|sql" | more

My initial problem was saving history (for backup to be used during
troubleshoot analysis) of plan changing and so on.. of the pg_statistic
table/object.

I was surprised - in a good way - to observe so much effort when handling
it for that specific purpose. I started to wonder if/when I want to create
an object of other *pseudatatypes *or pass it through a function parameter
that the same level of effort during code implementation would be the same.

I understand this would be much more a code architecture discretion rather
than a punctual question.

I have posted in pgsql-admin a question which is "simple problem" when
creating a table using anyarray and indeed the problem is simple - the
solution might not be.

What folks, more experienced in this subject, would recommend as a starting
point to achieve that objective?

Kind regards,

Bazana Schmidt, Vinícius

PS.: apologize in advance for the HTML email.