So I’m gonna chime in with the annoying note that Sibelius makes this very easy.
@dspreadbury, these are not combined dynamics indeed–they are common instructions to play different dynamics on different passes and in Sibeilus, OP could type “mp-p” and away they go.
I’ll use my current example: I’m transcribing ‘Hip to be Square’ and a sax line goes around in the outro. I’m writing that line for three horns with the sax going first, crescendoing throughout and the trumpet and trombone joining after a repeat. Ideally, I want the sax to have mf-f so that we’re joining him at the same dynamic of f after the repeat.
Dynamics on different passes are very common and I’m surprised they’re not supported by default–from what I know, your team has some good experiences of pop and jazz music among your ranks, but this is also common in orchestral settings too.