Even If (Hypothetical Concession)

It is the degree that will not change the outcome, not the possibility.

どんなに～ても vs ～たとえ～ても: Use どんなに〜ても: however much, however hard. たとえ〜ても grants that something might happen at all, which is a weaker claim, so it undersells a sentence about no amount of effort being enough.

Granting someone's point in conversation before pushing back.

～にしても vs ～たとえ～ても: にしても is the conversational 'even granting that', and it can pick up something already said (忙しいにしても連絡ぐらいは). たとえ〜ても sets up a hypothetical from scratch and is heavier than a quick concession needs.

Granting a supposition and denying that it would change anything.

～としたところで vs Verb ないまでも: Use としたところで. It concedes the case and then dismisses its force ('even supposing so, it makes no difference'). ないまでも does the opposite: it falls short of a maximum but keeps a positive claim ('not quite X, but at least Y').