I think it's appropriate with the imagery Keir wants to portray and I don't think it will lose him any votes, I'm sure you'd agree it's not much of an issue to begin with.
I'm not dying on any hill over anything here, I personally believe Labour suffered from being on the fence from 2014 and are now consciously pitching their tent in the Unionists camp, they'll not try and out Tory Tories but instead probably push the more devo stuff and try and win back votes from people who didn't like Corbyn/Brexit etc..