I’m not technically arguing against anything, as I said, to each their own. I was simply adding my opinion. Makes no difference to me what an internet stranger carries. As far as a derailleur, are you serious? Maybe it’s the mechanic in me coming out but, you should never be adjusting your high and low settings on the side of the road. That’s the type of maintenance that should be done at home before setting off, because all those screws do is set how far inboard and outboard the derailleur can swing. Failure to do that before riding is just laziness, not a good case for a multi tool. Hell, a keychain Swiss Army knife could handle that. Nearly anything could work to adjust those two screws. Besides that, once they are set the first time, they should never need adjusting again anyway. Also, we’re in the ss/fixed gear section aren’t we? So aren’t we under the assumption that the OP doesn’t have a derailleur on their bike? Or am I wrong?