Tremolo symbol with tremolo channel

I've created in my custom palette a text symbol with attached the tremolo channel (for string instruments) to reproduce the tremolo effect instead of using the default helicopter one (something similar to the "arco" or "pizzicato" text in fact.
(I add the symbol to all the visually necessary notes, although for the sake of the sound it is needed only on the first note).

I was just wondering whether the plugin capabilities allow us to:
1. Given a note selection, add this symbol from the custom palette to all the notes
2. place it in a convenient way like the default tremolo one (at leat the first time)
3. add an invisible "arco" text to the next available note/pause

By the way, this makes the score reproduction way smoother, without any "scratching / messy" sounds where there are too many standard tremolo symbols (I already opened another bug for that).

That's all :)