Allow for (or automate) continuation text for trill lines
Currently if you insert a trill line that spans systems, the trill line on the second system only has a line with not "tr" at the beginning of it. This is confusing because this is identical to the line called Guitar vibrato, but in version 2 it was called a Prallprall line which now seems to be missing. If you don't know where you are going to insert a page break in advance you put the trill line over all of the affected notes. You would expect "tr" to display at the beginning of the line (like on cresc. lines) automatically.
The bottom line for the request is to either automatically put a tr at the beginning of the new system. This is acceptable because I've never seen it without the tr. You can allow for the user to adjust the continuation text as with other lines if this is easier.