尚(なお) ②In addition, Incidentally, Furthermore, Moreover

なお② and その上 are both formal expressions used at the start of a sentence to add information. They can overlap in meaning, but その上 often implies that the following point is notable, while なお② simply adds on. Additionally, requests or instructions can follow なお②, but usually do not follow その上.

なお② and それに both add information, but differ in tone. それに is neutral and used in everyday speech. なお② is formal and often written, with a tone of explanation or emphasis, e.g. 商品の仕様は変更される場合があります。なお、返品はできません ('The product specifications may be changed. Furthermore, returns are not accepted.').

なお① expresses persistence or continuity, indicating that a situation remains unchanged despite other factors, often with a nuance of unexpectedness, as in 病気が治ったが、体力はなお弱い (The illness is cured, but my strength is still weak). なお② adds supplemental information, drawing attention to further details, as in 詳細はなおご説明します (I will explain further details).

しかも and なお② both add additional information, but differ in nuance. しかも often strengthens the previous statement with surprising or emphatic detail, as in 彼は優秀だ。しかも努力家だ (He is talented, and what’s more, hardworking). なお② is more neutral and formal, used to supply further facts without emphasis, as in 今回の件について、なお調査中です (Regarding this matter, we are still investigating further).