I'm currently in a karmic relationship, and the day we met transiting Uranus and transiting Node were conjunct our composite MC, and transiting Pluto was conjunct composite 7th house cusp, as well as transiting Uranus conjunct my progressed MC. The day my ex-wife and I got together (another karmic relationship) transiting Pluto was trine our composite Sun, and transiting Jupiter was trine composite Venus. Transiting Uranus was also conjunct my natal MC. The day we met (several years earlier) transiting Pluto and transiting Node were trine composite Saturn (Pluto within a couple of minutes), and transiting Jupiter was opposite composite MC, and transiting Uranus was sextile composite Saturn, transiting Neptune opposite composite Jupiter (partile), plus more. All aspects listed were within 2 degrees. So yes, I think transiting aspects have a major function with composite positions, but possibly only with people you have fated, karmic connections with. Passing acquaintances - possibly not.