Yep, that chromatic aberration is a killer.
Try fixing acquisition/optics first, but there is there is one last thing you can do in post-processing.
In the Develop module ("stretch as-is" if you're otherwise happy with your stretch), you can use the luminance contribution mixer to take away all luminance contribution by the blue channel. This means that for any detail, only the red and green channel are used; color information is still used from all channels (including blue). This feature was mainly meant for planetary imaging where certain bands may be very polluted/unreliable/susceptible to atmospheric interference.
It's not a great solution for blue nebulosity (though you can apply the luminance mixing to just the stars - e.g. "fat stars" preset - using the Layer module and the undo buffer)
Your stars can definitely be salvaged, however it's a lot of work and custom processing; something that's fine if you know what you're doing but I wouldn't recommend it part of a staple work flow...
The above was accomplised by applying decon (in Planetary mode, e.g. no mask used at all) to the blue channel (all image pre-binned to 50%), shrinking the stars using the Magic module and re-merging it with red and green in the LRGB module.
The Develop module was used in the manner described above ("stretch-as-is") after I used AutoDev with a ROI over a star for the general stretch.
The final result (after switching Tracking off) was put through the Fringe Killer to remove any strong/deep blue.
StarTools is pretty powerful and will let you do all this if you really want/need to, but, again, it's always best to address these issues at the acquisition stage.
Hope this helps at all!