A new script hlpvitem.py is now available. It displays item in a bar (like status) with highlight or private message, from an hidden buffer. So you will see content of message before switching to that buffer.
You must add item in a bar, like status, with this command:
/set weechat.bar.status.items
then press "Tab" and complete string by adding for example (without quotes): ",[hlpv]"
Screenshot:

You can setup some options with /set:
/set plugins.var.python.hlpvitem.show_all_buffers on/off (default: off)
/set plugins.var.python.hlpvitem.buffer_number on/off (default: on)
/set plugins.var.python.hlpvitem.buffer_short_name on/off (default: on)
/set plugins.var.python.hlpvitem.highlight on/off (default: on)
/set plugins.var.python.hlpvitem.private on/off (default: on)
/set plugins.var.python.hlpvitem.string_highlight "string" (default: empty)
/set plugins.var.python.hlpvitem.string_private "string" (default: empty)
/set plugins.var.python.hlpvitem.string_delimiter "string" (default: " > ")
/set plugins.var.python.hlpvitem.color_string_highlight color (default: empty)
/set plugins.var.python.hlpvitem.color_string_private color (default: empty)
/set plugins.var.python.hlpvitem.color_buffer_number color (default: empty)
/set plugins.var.python.hlpvitem.color_buffer_name color (default: "default")
/set plugins.var.python.hlpvitem.color_prefix color (default: "white")
/set plugins.var.python.hlpvitem.color_delimiter color (default: "cyan")
/set plugins.var.python.hlpvitem.color_message color (default: "default")
/set plugins.var.python.hlpvitem.visible_seconds N (default: 7)