Acros vs Pancro 400 for Astrophotography

At GSSP 2019, I tried using the listed films for long exposures of the night sky.  
Acros has a well-known great reciprocity failure characteristic of just a half stop for exposures longer than a minute.  Unfortunately, it’s nearly blind to the Ha spectrum, meaning that it won’t show the red nebula of cloudy milky way galaxy.

On the other hand, the datasheet for Pancro suggests that this film might be able to see the red colors.  Thus, I did a trial to see what could be found.  The exposures were 40 minutes at F5.6 on this 400 mm lens.  A clear Hoya UV filter was used to achieve infinity focus.  

Focus was checked with a digital camera and bahtinov mask.  Purple fringing was apparent on the bright stars.  It was strong wide open at F4, gone by F8.  I didn’t want to shoot the lens at F8, so opted for F5.6 as the best compromise.  I expected some star bloat due to the fringing.

For this Ha check, the targets were NGC 7000, IC1396, and M27.  These are all bright objects and will show some nebulosity.  Again, the exposures were as above.  

Also, an image of M31 was done for a check on wideband target.

Film was developed according to the MassiveDevSheet website at full strength Xtol.

The negatives show lots of stars, but are very thin.  

Nebulosity is barely recorded.  Even Acros has better response to Ha than Pancro400.

M27 shows as a tiny barbell - showing that the OIIII responded well.
NGC 7000 shows as a grainy shadow when a deep scan is done with contrast and midtones pushed hard.