Dynalist has a new update which adds a feature that I personally find very useful: non-adjacent selection.

They also say: "We’ve received several reports about how the app freezes or crashes when there are too many items in a document. We’re looking into the problem!"

http://blog.dynalist.io/2017-week-26-update/

oops, can't seem to edit the typo in the title? Ads/adds...