Option to change line color per object
Display line color next to object select (allow set of line width,opacity also, option for time tickmarks)

pull settings from url, localstorage

arbitrary lines for protractor

analemma

satellites

For non-sun object, show sky path line in different color based on day/night time

Change orientation on mobile does not re-init canvas size

Twilights, Golden hour, Blue hour

Eclipses and occulations

Custom RA/Dec points

Commets

Moon rise/set recomputed at actual times rather than current time

draw moon as image with phase and parallactic angle

Map tile options
https://leaflet-extras.github.io/leaflet-providers/preview/