This says it all: https://makemusic.zendesk.com/hc/en-us/community/posts/115000723668-shorten-note-duration

I also asked my recent complaint about this be passed onto the Project Manager. (Did you get it?)

Some have claimed this need is properly handled by the DAW one exports MIDI from. This is bogus for the following reasons:

1. the same need will arise if one enters notes into Finale manually and then CHANGES ONE'S MIND, AS COMPOSERS DO! and decides to notate, say quarter notes as 8ths followed by an 8th rest. Or vice versa.

2. Finale's Change Duration tool is misnamed. You would be ashamed of it and fix it if you named it by what it does: Finale's Change Duration and Rhythm Tool.

Please reconsider and add this tool. (NOW you're being nice, Burt, after ranting at these poor people!  ;). )