I've been playing the game with no shield recently and just poking around to see if there were any benefits from doing this.
Call me crazy but I think the your dash is 1 square longer if you have no shield. Can anyone else confirm this?
If no, maybe there is an old thread talking about this that you can link me to. The Forum search bar doesn't function and leads to a 408 thing.
Don't use the forum search bar, instead search using google with the tag "site:forums.spiralknights.com" in the searchbar.
And honestly, all the things you give up without a shield (shield canceling, flash charging, blocking shots, switch-shooting, maintaining combos while stationary, shield bash, etc.) wouldn't be enough to warrant giving up a shield if you do gain one block farther to dash. I highly doubt the dash is a true statement however, unless you're using a MSD shield potentially.
Pretty easy to test as well if you find "tiled" blocks. In a clockworks terminal it's pretty easy to do.