Foy my public sector organization, we have two committee meetings the day before the board meeting, and a third in the morning before the afternoon Board meeting. Each of the respective committee chairs prepares their own verbal report for the board, effectively drawing from the committee meeting agendas and their own notes, and with reference to the Board's consent agenda. 

Staff are not involved, except perhaps if a Chair needs something clarified. We do particularly appreciate that one committee chair regularly shares with us his speaking notes after delivering them.  

This approach is most challenging for the chair of the committee that meets the same day as the Board -- minimal to no time to reflect or assemble notes. However, at least the proceedings are fresh in mind.

And, at the Board, no one objects if another committee member supplements the Committee Chair's report with additional thoughts or detail where warranted.

That's what we are thinking of doing too. A draft outline based on the agenda and maybe having the Executive lead for that item provide one or two high level points.

During my volunteer gig, I asked each sub-committee Chair to provide a written  summary (high-level points) of their activities for the Board.  The Chair's were encouraged to extract the main points from their minutes to reduce time spent on this task.  These reports were provided 1 week in advance of the Board meeting so the discussions were focused and decision making went smoothly.

At my place of work, I synthesize the Executive Committee's minutes into a monthly report for the Board.  This document is provided 1 week in advance of the Board meeting.  Feedback has been extremely positive.

As a side note, none of our Board members, save and except for the President, receive any remuneration (volunteer gig) so I am always looking to make their time and effort worthwhile.