TLDR: Tap and hold on a comment to collapse it.
I was missing the feature from RiF that let you hide and collapse comment chains. I only just figured out how to do this on the Connect Android app.
By pressing and holding on a comment you hide that comment and all replies to it letting you easily skip down to the next parent comment.
So does Jerboa. I keep hitting it by accident.
I keep collapsing the sub-comments because I keep thinking long pressing on the main comment = the context menu of the comment