How to find all portal glyphs without using a 2 glyph portal?

how does the spawn of travellers work? Do I just keep jumping stations until I find one? I did that yesterday but could not find a single one. Any ways to speedrun this, ofc without using the 2 glyph portals? Maybe I have to check them on specific location when I dock on space stations? I have found 6 glyphs, maybe that is the limit? Has the new update changed their spawn mechanics or something?