Update: I've added a second tool to the page that is focussed around cleaning up a KML from the first GPX to KML tool or could have stand-alone value. It allows you to sort the control (all or just the S1/F1), remove the <description> tags, change the internal Course name used in the file and renumber if desired.
Based on the initial question and discussion started by Guy about directly using a Checksite to produce a KML,
Forum Thread I initially added to my MapRun tool (windows based) a conversion function but after realizing that this feature might be more useful than I first anticipated, decided it was time to learn some web scripting (PHP in this case). So ...
Checksite to KML ConversionThe Home Page has a fairly detailed explanation. Using a Checksite provides the ability to drop waypoints along the route and add a description to each. This can be used to note good control locations or adjustments, pinpoint specific features etc. You could also produce a fairly good draft KML of your complete course by walking around and dropping waypoints where you want them (something Guy has been playing with). As a minimum it allows you to open the resulting KML in Google Earth along with another draft KML and compare/adjust as needed. If desired, you can embed a Control Code into one or more of the Waypoint descriptions which will then be used in the KML. Otherwise, Control Codes are automatically added. Again, more details and examples on the home page.
The intent is not to produce a final KML for MapRun but a draft based on your input - so, as an example, if you do not have the Start and Finish in the waypoints (or at the beginning and end) this will be reported but not changed.
I've attached a sample GPX (it has had a bunch of trackpoints removed to reduce size) if you want to give it a try and see how embedded control codes are parsed.
MapRunF_Track_Sample.gpx