A lot of the topics covered in this thread are dealt with in detail in the 2017 review paper I cited in my original news article on this comet:
https://link.springer.com/content/pdf/10.1007/s11214-017-0446-5.pdf
It is well worth a read. See, for example, section 6.2 which discusses the breakdown of the inverse square law in relation to, amongst other things, heat flux.