[Meo-Ada Mespotine]

1 day, until you can finally:

Get the current Marker/Region at mouse-position, the graphical-size they are drawn as into the arrangeview:

-- Ultraschall-API demoscript by Meo Mespotine 30.11.2018
-- 
-- shows, which markers/regions are underneath the mouse-cursor


dofile(reaper.GetResourcePath().."/UserPlugins/ultraschall_api.lua")

function main()
  -- get mouseposition, markers and regions as well as the mouse-context
  x,y=reaper.GetMousePosition()  
  marker=ultraschall.GetMarkerByScreenCoordinates(x, false)
  region=ultraschall.GetRegionByScreenCoordinates(x, false)
  window = reaper.BR_GetMouseCursorContext()
  
  -- if the markers/regions underneath the mouse have changed and if mouse is in ruler, 
  -- show the currently found markers and regions in the ReaConsole-window
  if (marker~=oldmarker or region~=oldregion) and window=="ruler" then
    if marker=="" then marker="\n\n\n" end -- small hack to avoid the output being 
                                           -- too jumpy when no marker is found
    reaper.ClearConsole()
    reaper.ShowConsoleMsg("Found Markers: \n"..marker.."\n\nFoundRegions:\n"..region)
  end
  
  -- keep the old values to check next defer-cycle, whether anything has changed
  oldmarker=marker
  oldregion=region
  
  -- start the next defer-cycle
  reaper.defer(main)
end

main()

and to show something else as well:

...you can store extstates for MediaTracks

-- Ultraschall-API demoscript by Meo Mespotine 11.12.2018
-- 
-- store new ExtStates for the first selected MediaTrack

dofile(reaper.GetResourcePath().."/UserPlugins/ultraschall_api.lua")

-- get the first selected MediaTrack and it's name
track=reaper.GetSelectedTrack(0,0)
if track==nil then return end
retval, name = reaper.GetTrackName(track,"")
if name==nil then name="" end

-- get the extstates stored with this MediaTrack
storedextstates=""
for i=1, 5 do
  temp, temp2 = ultraschall.GetTrackExtState(track, tostring(i))
  if temp2==nil then temp2="" end
  storedextstates=storedextstates..tostring(temp2)..","
end

-- show the inputdialog, with the already stored extstates as default
retval, retvals_csv = reaper.GetUserInputs("Set TrackExtStates "..name, 5, "01,02,03,04,05,extrawidth=300", tostring(storedextstates))
if retval==false then return end

-- separate the returned inputfields into an array
count, vals = ultraschall.CSV2IndividualLinesAsArray(retvals_csv, ",")

-- set the new ExtStates to the MediaTrack
for i=1, 5 do
  retval = ultraschall.SetTrackExtState(track, tostring(i), vals[i],true)
end

-- Ultraschall-API demoscript by Meo Mespotine 11.12.2018
-- 
-- retrieve and display ExtStates for the first selected MediaTrack
-- will be displayed in the ReaScript-Console

dofile(reaper.GetResourcePath().."/UserPlugins/ultraschall_api.lua")
-- prepare some variables
oldoutput=""
oldtrack=""

function main()
  -- get the first selected MediaTrack and it's name
  track=reaper.GetSelectedTrack(0,0)  
  if track~=nil then
    retval, name = reaper.GetTrackName(track, "")
  
    -- Get the ExtStates store with the first selected MediaTrack
    output=""  
    for i=1, 5 do
      temp, temp2 = ultraschall.GetTrackExtState(track, tostring(i))
      if temp2==nil then temp2="" end
      output=output.."    "..i..": "..temp2.."\n"
    end
    -- if extstates have been changed or the selected MediaTrack has changed, display the
    -- extstates into the ReaConsole-window
    if oldoutput~=output or oldtrack~=track then reaper.ClearConsole() reaper.ShowConsoleMsg("Showing ExtState for track: "..name.."\n\n"..output) end
    oldoutput=output
    oldtrack=track
  end
  -- repeat the whole thing
  reaper.defer(main)
end

-- let's boogie
main()

as well as for MediaItems. When ItemNotes are not enough:

-- Ultraschall-API demoscript by Meo Mespotine 11.12.2018
-- 
-- store new ExtStates for the first selected MediaItem

dofile(reaper.GetResourcePath().."/UserPlugins/ultraschall_api.lua")

-- get the first selected MediaItem and it's name
item=reaper.GetSelectedMediaItem(0,0)
if item==nil then return end
name = ultraschall.GetItemName(item)
if name==nil then name="" end

-- get the extstates stored with this MediaItem
storedextstates=""
for i=1, 5 do
  temp, temp2 = ultraschall.GetItemExtState(item, tostring(i))
  if temp2==nil then temp2="" end
  storedextstates=storedextstates..tostring(temp2)..","
end

-- show the inputdialog, with the already stored extstates as default
retval, retvals_csv = reaper.GetUserInputs("Set ItemExtStates "..name, 5, "01,02,03,04,05,extrawidth=300", tostring(storedextstates))
if retval==false then return end

-- separate the returned inputfields into an array
count, vals = ultraschall.CSV2IndividualLinesAsArray(retvals_csv, ",")

-- set the new ExtStates to the MediaItem
for i=1, 5 do
  retval = ultraschall.SetItemExtState(item, tostring(i), vals[i],true)
end

-- Ultraschall-API demoscript by Meo Mespotine 11.12.2018
-- 
-- retrieve and display ExtStates for the first selected MediaItem
-- will be displayed in the ReaScript-Console

dofile(reaper.GetResourcePath().."/UserPlugins/ultraschall_api.lua")
-- prepare some variables
oldoutput=""
olditem=""

function main()
  -- get the first selected MediaItem and it's name
  item=reaper.GetSelectedMediaItem(0,0)  
  if item~=nil then
    name = ultraschall.GetItemName(item)
    if name==nil then name="" end
  
    -- Get the ExtStates store with the selected MediaItem
    output=""  
    for i=1, 5 do
      temp, temp2 = ultraschall.GetItemExtState(item, tostring(i))
      if temp2==nil then temp2="" end
      output=output.."    "..i..": "..temp2.."\n"
    end
    -- if extstates have been changed or the selected MediaItem has changed, display the
    -- extstates into the ReaConsole-window
    if oldoutput~=output or olditem~=item then reaper.ClearConsole() reaper.ShowConsoleMsg("Showing ExtState for Item: "..name.."\n\n"..output) end
    oldoutput=output
    olditem=item
  end
  -- repeat the whole thing
  reaper.defer(main)
end

-- let's boogie
main()