By default, Joomla provides few types of fields that could be used as repeatable custom fields:
I want to have more fields like boolean, or maybe even more rich like "select article".
I know that there is the possibility of overriding the files, but I am a bit scared of losing them after update.
For example, I managed to add checkbox fields by adding new string to file located at:
How can I achieve this in an update-safe way?