No, it's not appropriate. Deku is a character with his own depth, goals, and story within the MHA universe. Fanfic should aim to explore his hero journey, his relationships in terms of mutual respect and support, not create content that focuses on inappropriate or disrespectful ideas like this.
I don't really have a list of specific 'mha deku x boobs fanfic' as it might lead to some inappropriate or objectifying content. Instead, if you like Deku, you could search for fanfics that focus on his growth as a hero, his friendships, and his challenges. For example, there are many fics that explore his relationship with All Might or his classmates in a positive and meaningful way.
One popular dadzawa fanfiction might be those where he mentors the young heroes in unique ways. For example, in some stories, he helps a troubled student overcome personal demons by using his calm and understanding nature.
One popular dadzawa fanfic might be the ones where he mentors a young hero in training. In these stories, Dadzawa shows his caring side while also being strict in teaching combat and survival skills.
Often, Midoriya Izuku is paired with Dadzawa in fanfiction. Their relationship can be explored in terms of Izuku's growth as a hero under Dadzawa's guidance.
Another option is to check out some Tumblr blogs dedicated to the fandom. Some bloggers might recommend or even post their own dadzawa fanfics. You can also join relevant fandom groups on social media platforms like Facebook or Reddit, where fans often share their favorite fanfics.
One common theme is protection. Aizawa is often shown protecting his students from villains or other dangers. Another theme is mentorship, as he guides the students in their hero development.
The main differences are in their expressions and some minor details of personality. In the manga, Deku might seem a bit more intense, while in the anime, he's sometimes presented a bit softer.
In 'deku meets future deku fanfiction', perhaps the future Deku warns the present one about upcoming threats. He could tell him about villains he'll face in the future and how to defeat them. This would give the present Deku an edge in his battles and also in his growth as a hero.
Well, obviously Deku in two forms - the younger and the older version are the main characters. The younger Deku is the one who is still growing and learning, while the older Deku has more experience.