Table Popup Row Actions: Add "Next Record" Button

I now also have this need.  Our team needs the ability to rapidly scan recent Activity when they are in a call, and this would help a lot.  Any hints on how I might implement some snippets to do prev/next? 

I see I have some interesting data in the arguments[0] (params), including the model, row and item/list, and can easily insert buttons to do multi-step actions w/snippet calls and model refresh.  Any pointers on how I might go about doing a prev/next on the table and then query the model again to refresh the popup fields?

Thanks!