Hello again.
I've no reason to use the Score Editor myself for what I'm doing, so don't get your hopes up!
I would like to drag a dot from the palette and put it on the first note of the first triplet and then have a way to apply this dot to all the following notes
But as a musician, I don't get what that means - usually, triplets are three notes played evenly over the space of one beat (or more beats or even subdivisions of the beat in theory) - just from my own memory, a lot of Debussy's piano music shows sets of 11, 17, 25, whatever number of notes to be played evenly within a certain number of beats/crotchets/semiquavers etc.
Is that what you mean ?
Maybe someone with a handle on scoring could give us a clue ?