Custom actions work well with VoiceOver and Switch Control. It is also a way of speeding up navigation, and grouping all actions available for an item in a single place, with Full Keyboard Access. Focus an item and use the shortcut Tab (⇥) + Z.

A tweet is selected when using Full Keyboard Access Navigation. If you use the shortcut tab + z, an activity menu will show with all the actions you can perform on that tweet, including reply, retweet, like, share via..., copy text, more actions and drag item.