I think steelmanning is good, depending on how much time you have for the debate. Obviously if you're going to be working on something for days with this person they should understand your position in detail and vice versa, but if you only have a couple hours or less for a debate it saves time without devolving into a point scoring war.
These are not arguments against steelmanning -- these are arguments against doing something else and calling it steelmanning. In other words, this is strawmanning steelmanning.
i.e. No matter your opinions, make your best case for why this is a good idea.
See also: strawman