MUSE map of the central Orion Nebula (M 42).   

It is a cube, the value is in coverage column: 2.9800000334e-07

Items 1 and 2 are addressed in IRSA-2396 and the implementation should follow what is requested there at this point. Xiuqin Wu [X], if you still want to use this DM ticket for the chargeable work, we should probably edit it accordingly.

Items 3, 4, and 5 should be addressed in a separate IRSA ticket. This is not priority work for LSST-DM post-descope.

Item 6 appears to be no longer needed, as the HiPS selection dialog is stretchable.

There is no plan to work on those items within current SUIT plan.  I will look into this again after we finish what we planed for LSST first. 

That's fine with me.

Items 1 and 2 are expected to be addressed soon.  The precise plan that's been agreed within the Firefly CCB for these is in IPAC ticket FIREFLY-213.  Quoting:

• Firefly should convert the units of the pixel scale column from their native degrees to arcseconds, by multiplying by 3,600.
• The pixel scale column should be displayed in scientific notation, x.xxe+yy (three total digits of precision). The limited precision is acceptable because the HiPS format only has a discrete set of pixel sizes on a factor-of-two ladder. (I.e., in principle even a single digit would be sufficient.) The currently expected range of values will be from 6.29e-03 to 1.65e+03.
• The coverage column (moc_sky_fraction) should be displayed in scientific notation, x.xxxe+yy (four total digits of precision). The limited precision is appropriate because the hipsgen software appears to only generate four significant figures in the {{properties}}file in the first place. The currently expected range of values will be from 2.980e-07 to 1.000e+00.

Item 6 is no longer needed, as the dialog has been made stretchable.

Items 3-5 (which are about supporting users in choosing which cubes are interesting to display) are still valid but are a very low priority for LSST and for IPAC in the near term since a) IPAC isn't currently generating HiPS cubes, and b) the current HiPS cube format is not suited to displaying data like the LSST ugrizy layers in which the z-coordinate is not on a regular, linear grid.

SPHEREx will be generating O(100)-wavelength-plane all-sky maps in the 2024 era.  As the SPHEREx wavelength grid is also not linear across the full range, we have a motivation from both LSST and SPHEREx to pursue with the IVOA an extension to the HiPS cube format to support a more general model for attaching a wavelength value to each plane.