Installing a set of Tektro HD E350 hydraulic disc brakes on a New Surly ECR frame and there are no cup and cone adjusting washers in the hardware kit. Are they required or only needed if there is an alignment issue?

My Soma B-Side with Avid BB7 mechanical brakes has them, but my Niner Jet 9 Shimano XT bike doesn’t ( bought second hand). The XT hydraulic brakes are by far the best I have used to date; power and modulation control is wonderful. This makes me think the adjusting washers are only needed if there is an alignment issue. What do trained bike mechanics say?

Thanks.