にしても・としても: the difference
にしてもN3
Meaning
Even though, Even if, Even when, Also
Past papers
Example
テスラモデルＳにしても、この値段は高すぎる。
Even if it is a Tesla Model S, this price is too expensive.
としてもN2
Meaning
Even if
Past papers
Tested 5 times in past papers
Example
たとえできるとしても、やらないだろう。
I wouldn't do it even if I could.
How to tell them apart
In 「にしても」 the first part is mostly a fact or reason that really exists. The speaker gives way on it, but says what follows crosses a line.
「としても」 leans toward a pure assumption; the first part is not necessarily true.
「とはいえ」 is the written 'having said that', calm in tone.
The second half often has 「～すぎる」, 「～べきだ」 or 「～はずだ」.