Just because there is space does not mean you need to fill it. The common app allows for space to prioritize listing you ECs and honors - make the most of those areas and use the supplemental essays to highlight your interests and experiences.
Those “additional information” spaces are mostly there to explain extenuating circumstances, traumatic situations that impacted a typical high school path, etc…
AOs typically warn about the misuse of the additional spaces, so unless you are explaining something that did not have another place to logically go…they may be annoyed by what they could perceive as arrogance in using a space created for actual situations to be explained.