Those are exactly the positions you should try hardest to steelman. Fundamentally the purpose of steelmanning is to convince yourself of the strongest arguments for a position, which you can then counter.

You are thinking of a good faith opposing argument. Not an argument where the other person is just trying to waste your time.

Very much disagree - in a bad faith argument, countering does nothing, because the point is not to prove their position, the point is to hurt you, or play to their base, or to tire you or distract you and generally just to waste your time.

It’s more of a “the only winning move is not to play” situation. You win by refusing to take the bait, and shutting down the attempt to coerce you into playing along with the bad faith argument game.

Or, if you like - when faced with “heads I win, tails you lose,” the strategy is not to figure out a way to get the coin to land on its edge, or to end up suspended in midair, or to propose some sort of infinite ‘best two out of three’ regress - the strategy is to recognize the rigged game and walk away.

There's understanding disagreeable viewpoints and the there's failing to adhere to the paradox of tolerance.

There's no reason to steelman "black people shouldn't exist in the US", as the most extreme example. I can steelman it, but what am I getting out of this? What am I professing to an audience to steelman this? Steelmans are used to build empathy and sh synthesize solutions taking multiple viewpoints into account. This is the opposite.