First off, LOVE the way you ask a question, nicely detailed.
More often than not when a burnt smell is coming from a laptop it's because a short circuit is occuring somewhere. The heat you talk about (around the ssd) correlates nicely with a short circuit, more rarely however, it can be a capacitor being strained or blown out and even a piece of debris that is being burnt.
Personally I would disassemble it, clean out all heatsinks and replace all cooling paste and looks for any signs of singed plastic, soldering or capacitors. (the top of a capacitor is flat normally and will bulge out and be singed when blown.)
I really hope this helps.
Good luck!