I didn't see any further suggestions here so I wasn't sure if this has been set or if you need more suggestions or not, but here goes my opinion.

I think selecting needs to be more consistent with other programs that people use to be more intuitive. I have two suggestions for how selecting multiple measures, when those measures are on two different pages on the screen.

1) The most intuitive would be to select the first measure and move your mouse to the bottom of the page, and then the score would smoothly scroll down so you could stop at the appropriate measure. This also works with the suggestion I saw about wanting smooth scrolling.

and/or

2) One way this is done in word processing software as well as selecting text in a webpage, would go something like this: First select the start measure of the region you want to select. Then use the "next page button" to view the end measure you want to select, then push and hold the "SHIFT" key and left click the final measure. This should select the first and last measure and everything in between.

Possible third way would be similar to number 1). You select the first measure and click and drag to the bottom of the page. If the mouse goes to (or past) the bottom of the page for more than 1 sec (approx) then have a pop up appear that asks for beginning and end measure. Hopefully the first measure will already be filled in.

Just some thoughts.