I've been using glueless patches for about 20 years and I don't have issues with sticking them over the seams.

By the way the thing about tubes not having seams is not true entirely correct, tubes are formed from one sheet of butyl and is then rolled and seamed together by heat which in my way of understanding is a seam but the two sides of the tube did have to be joined together along that line. There are some other marks on some tubes that are mold channels but most tubes are seamed together; see: https://www.youtube.com/watch?v=X4cQ-R6ysmw Here's another video on how tires and tubes are made, at about 7:37 into the video the tube presentation is shown; see: https://www.youtube.com/watch?v=V0P3oQWo22A This one is more high tech than the first video, but the butyl material goes into a machine as a sheet and then it is joined and extruded as a tube. Also they talk about cutting the tube and inserting the valve then the two ends are smashed together while the tube is hot and sticky and are rejoined, again i would call this another seam. Some, or all seams are so smoothly done you can't see them, but the tube had be joined and wherever that is is a seam.