Alasdair
I have tried to produce a more formal version of the napkin representation, using the data and metadata from Solano's example light curve. (see attached file napkin.xml)
The parameters have an attribute "utype" which refers back the precise meaning defined in the spectrum DM, for example the start time for the light curve has the utype = sed:Segment.Coverage.Region.Time.Start.
I have put four quantities in each row, as you had, bus slightly different naming. My version has each measurement with four pieces:
<Time unit="day">1305.65557</Time>
<TimeExtent unit="s">30.00002</TimeExtent>
<Flux unit="mag">7.808</Flux>
<FluxErr unit="mag">0.012212</FluxErr>
How does this look?
Roy